Replaced AC Capacitor - Duo-Therm For It Is Blank

[woodylmiller]

Follow up:  cleaned all connections with alcohol and a spray electronics cleaner, and replaced the broken plugs and all new couplings.  Fan on middle unit came on, I turned off the power to the units to avoid anything else coming on.  After all the cleaning, checking the fuse marked "A/C" control, I now have no light or display on the thermostat.  Made a cheater cord to test for power and coupled that to the plug that connects to the thermostat.  I have 12.9 on one pair and almost 4 volts on the other.  Unless someone has a different take, I have to think at this point that the thermostat is bad.  I did read somewhere that there is a fuse in the thermostat.  I took it apart but if there's a fuse there, I can't find it.  One tip about taking the thermostat apart, watch the buttons, they fall off very easily and are tough to find on the floor.  Thoughts?

Woody Miller

09 Dynasty

[Tom Cherry]

35 minutes ago, woodylmiller said:

Follow up:  cleaned all connections with alcohol and a spray electronics cleaner, and replaced the broken plugs and all new couplings.  Fan on middle unit came on, I turned off the power to the units to avoid anything else coming on.  After all the cleaning, checking the fuse marked "A/C" control, I now have no light or display on the thermostat.  Made a cheater cord to test for power and coupled that to the plug that connects to the thermostat.  I have 12.9 on one pair and almost 4 volts on the other.  Unless someone has a different take, I have to think at this point that the thermostat is bad.  I did read somewhere that there is a fuse in the thermostat.  I took it apart but if there's a fuse there, I can't find it.  One tip about taking the thermostat apart, watch the buttons, they fall off very easily and are tough to find on the floor.  Thoughts?

Woody Miller

09 Dynasty

To the best of my knowledge….no fuses in thermostat.  Best way to test.  Take the Thermostat to the front and rear unit.  Here is where the info is sketchy on the Dynasty’s.  Folk have said they do not have the short “cheater” of extension cords that go from the Control module in the roof top portion….supposedly the data cables in the Dynasty was long enough to go up through the Plenum and directly to the female RJ11 Jacks.  If so, make up a data communication cable with the proper color codes or configuration on each end.  Then plug in the thermostat directly.  You can also verify 12 VDC on the controller board….pictures were published recently.  With the thermostat plugged in to either female jack, do the RESET.  IF the thermostat is OK, it will function there.  Obviously you will only have Zone 1….unless you leave the outlet cable in place.  Try it on the rear AC as well.

if it is dead, Northwest RV Supply had a refurbishment option.   Contact them
 

Testing at a unit directly is the only proven method….unless you have special data signal (analog for Voltage & digital for the MPX pair).  

[woodylmiller]

Thanks Tom.  I have two cables at each unit and dangle in the plenum.  Currently nothing on the thermostat, no backlight, no display.  As luck would have it, the 5 button thermostat is no longer available.  Calling NWRV Supply today.  If they don't have it, I see MicroAir makes a replacement, though a little pricey.  It's both wifi and bluetooth so might make a nice upgrade if nothing else.  I'll check for the 12 volts at the unit.  Have cleaned everything and all the 3 amp fuses are good.  Good advice to check each unit by direct connect to the thermostat.  Thanks again.

Woody Miller

09 Dynasty

[Tom Cherry]

8 minutes ago, woodylmiller said:

Thanks Tom.  I have two cables at each unit and dangle in the plenum.  Currently nothing on the thermostat, no backlight, no display.  As luck would have it, the 5 button thermostat is no longer available.  Calling NWRV Supply today.  If they don't have it, I see MicroAir makes a replacement, though a little pricey.  It's both wifi and bluetooth so might make a nice upgrade if nothing else.  I'll check for the 12 volts at the unit.  Have cleaned everything and all the 3 amp fuses are good.  Good advice to check each unit by direct connect to the thermostat.  Thanks again.

Woody Miller

09 Dynasty

Before I spent ANY MONEY….I would test the thermostat directly on the front unit,,.,using the dangler.  If it is blank…odds are….bad Thermostat.  From my “catalogued and precise” cranial data base….accumulated over 15 years.  90% is cables or connections.  Maybe split evenly between a bad Control Module and a bad 5 button.  Mine has been apart….or at least where I cleaned the “button carbon”.  
 

Test the Tstat on all 3…..if all have 12 VDC….and you need to use your cheater to see the 12VDC….then if 12 VDC….from the control and a “blank stare” on the display….bad stat.  

[DBRV.0]

4 hours ago, woodylmiller said:

Good advice to check each unit by direct connect to the thermostat.

Woody,

I am a visual person, therefore for me, a diagram is worth at least a thousand words.  I did a little work on my 3-air conditioner system, and am now starting to understand some of the wire control concepts.  Here is a concept drawing that I made up of what I believe is the HVAC control wiring.  Because of ceiling decor, I have never looked at the interior air intakes of AC1 and AC2 to assess actual wiring, so what I have drawn is a guess.  One thing I know for sure is that topside on the roof, each Air unit has 2 RJ11 data / phone cord connectors that are interconnected, meaning each is identical in function.  Perhaps this diagram would help you to diagnose your setup.  The RJ11 has 2 wires in the cord that present 12VDC, but I am not sure where that 12VDC is "injected" into the RJ11 cords.

Tom mentions to connect your thermostat to AC1 or AC3.  You may understand his reasoning through the diagram.

If anyone can correct my concepts, I would welcome the information!

- Jeff

[Tom Cherry]

13 minutes ago, DBRV.0 said:

Woody,

I am a visual person, therefore for me, a diagram is worth at least a thousand words.  I did a little work on my 3-air conditioner system, and am now starting to understand some of the wire control concepts.  Here is a concept drawing that I made up of what I believe is the HVAC control wiring.  Because of ceiling decor, I have never looked at the interior air intakes of AC1 and AC2 to assess actual wiring, so what I have drawn is a guess.  One thing I know for sure is that topside on the roof, each Air unit has 2 RJ11 data / phone cord connectors that are interconnected, meaning each is identical in function.  Perhaps this diagram would help you to diagnose your setup.  The RJ11 has 2 wires in the cord that present 12VDC, but I am not sure where that 12VDC is "injected" into the RJ11 cords.

Tom mentions to connect your thermostat to AC1 or AC3.  You may understand his reasoning through the diagram.

If anyone can correct my concepts, I would welcome the information!

- Jeff

Thanks.  Only a little explanation

.  The older Dynasty MAY NOT have had the remote sensor on Zone 1.  i have “messed” with a few.  The 09 Patriot Thunders DID have a remote.  Otherwise, the Internal sensor in the Thermostat is the sensor for Zone 1.

Without pulling the prints, the routing is probably correct.  BUT supposedly Zone’s 1, 2 and 3 also redundant WITH  12 VDC lines.  Dometic says only ONE controller needs that.  The Zone 4 hidden controller did not, in the earlier years (2006 - 2008) have a 12 VDC line.

We have one recent example, supposedly measured by a member, of the Bedroom Zone 3, with NO 12 VDC.  Obviously Monaco never pretended to be perfect…but they DID intend to send the same (one fuse) 12 VDC power to the three (or two) rooftop units…

This is cool….it may show up again….  LOL….great job…

[DBRV.0]

1 hour ago, Tom Cherry said:

it may show up again….

Thanks for the encouragement, but you scared me into cleaning up the routing to improve clarity.

- Jeff

[woodylmiller]

I connected the thermostat to zone 1, front A/C, and still no display or back lighting.  Connected the cheater cord and got around 4 vdc.  Now, since the units do connect in series and if 12vdc is used in a series circuit, wouldn't that relate to 4vdc across the 3 loads?  Current is the same, but voltage is divided between the loads in a series circuit.  At least that's how I learned it in my electrical and electronics courses.

I checked with parts store in Eugene, and they have zero 5 button thermostats and about $150 to repair the 5 button, if it's fixable.  A new replacement from Micro Air is $240.  So the dilemma is $150 for a rebuild on my thermostat or $240 for a new thermostat with wifi and bluetooth.  Even if my thermostat is good/repairable, I wouldn't mind the upgrade to the Micro Air thermostat.  We are leaving in two weeks to head south for the desert to avoid the white stuff this year.  So I don't think I have time to send my thermostat out, get repaired and sent back to me.  Sounds like I'm going to go with the Micro Air.  And if that doesn't solve the problem I'll keep digging for a solution.  We go right past the REV service center in Coberg, OR.  So we'll see.

DBRV.O, I like your diagram, and I agree with it.

Thanks guys,

Woody Miller

09 Dynasty

[Tom Cherry]

8 minutes ago, woodylmiller said:

I connected the thermostat to zone 1, front A/C, and still no display or back lighting.  Connected the cheater cord and got around 4 vdc.  Now, since the units do connect in series and if 12vdc is used in a series circuit, wouldn't that relate to 4vdc across the 3 loads?  Current is the same, but voltage is divided between the loads in a series circuit.  At least that's how I learned it in my electrical and electronics courses.

I checked with parts store in Eugene, and they have zero 5 button thermostats and about $150 to repair the 5 button, if it's fixable.  A new replacement from Micro Air is $240.  So the dilemma is $150 for a rebuild on my thermostat or $240 for a new thermostat with wifi and bluetooth.  Even if my thermostat is good/repairable, I wouldn't mind the upgrade to the Micro Air thermostat.  We are leaving in two weeks to head south for the desert to avoid the white stuff this year.  So I don't think I have time to send my thermostat out, get repaired and sent back to me.  Sounds like I'm going to go with the Micro Air.  And if that doesn't solve the problem I'll keep digging for a solution.  We go right past the REV service center in Coberg, OR.  So we'll see.

DBRV.O, I like your diagram, and I agree with it.

Thanks guys,

Woody Miller

09 Dynasty

From the TOP.  There are TWO PAIR...  EACH IS SEPARATE and do NOT know that the OTHER exists.  One pair is the 12 VDC, that comes from the Control Module.  Every Control Module....assuming that Monaco actually "WIRED" it correctly gets 12 VDC.  

OK....back to basics.  Go back to PAGE 1 of this topic.  There is a picture of the Control Module....and the 12 VDC terminals are marked.  If you do NOT have 12 VDC coming into the FRONT module....then, that MAY be the problem.  BUT, if THEORY, from the drawing...which is a "template" for the actual prints...  If ONE unit has 12 VDC and the Data Communications Cable is connected (and is wired or color coded) properly....then the entire system works.

Now to address your voltages.  No one, to my knowledge, has ever commented on the MPX pair of the two pair data cable.  THEY ARE SEPARATE...  THEY DON'T KNOW EACH OTHER EXISTS (pardon my simplicity).  You MUST have 12 VDC on the single pair.....and, you can can do a continuity test on the Positive and Negative in the picture or on the board....with two of the leads in the cable.  Past that.... it is the THERMOSTAT that then takes over.  ONCE you have 12 VDC into the Thermostat....then it does a "handshake" with the other modules.  As LONG as there is 12 VDC coming to each module....via, in Zones 1, 2 and 3....then ANY ONE of them can provide power to the "system".  Zone 4 gets its JUICE or 12 VDC from the 12 VDC leads in the cable.

SO....  TEST for 12 VDC up front.....  Then test your DATA CABLE CHEATER CORD...assuming that you have the same LEADS .....  that is why you need to do a continuity test on the board and have your cable plugged in.  You MUST have continuity or voltage to the same PAIR of RJ11 Cable...

OK....now if the Thermostat is defective....then even though it has 12 VDC.....and it is "dead", then it can't send out the Handshake signal.  NO HANDSHAKE SIGNAL....NO WORK.

My next step would be to verify the front voltage....on the Control Board.  Then...if that is OK....  MOVE ON.  Go to Zone 3.  Do the same.  Then Zone 3.  If the Thermostat does NOT WORK on any of the modules....and you have 12 VDC on the two terminals (see the pictures)....then...  ODDS ARE...you have a bad Thermostat.

NOW...  Herein lies the dillema...and folks think that this is ANTI MICROAIR.  It is REALITY.  Microair know less about how the system works that we do here.  They are "COPY CATS".  They used a stock setup....and followed the Dometic prints.  It is called REVERSE ENGINEERING...and it very common in the electronics industry.  They cracked the DIGITAL CODE for the MPX signals.  They ran a full array of tests.  They then recorded or decoded the MPS codes.  SO....  that means that when the AC is on in Zone 1....and the temperature is satisfied....then there is NO MPX signal to the Control Board.  It is just there...in standby.  BUT....when the set point is exceeded....and the thermostat sends out a signal.....that MPX signal is a complex (maybe Hexadecimal) code.  The single pair of MPX leads works BOTH WAYS.  SO, the Dometic sends out a code that says...  START the compressor....as in... the temperature that the thermostat reads (the internal one....assuming there is NO remote on zone 3) had exceeded the set point.  THEN....the control module decodes that signal.  NOW, here is where it is sometimes confusing.  A MPX digital signal can go both ways....

SO....in essence...  The Thermostat is constantly monitoring Zone 2 and Zone 3 set points.  ONCE the remote sensor says "HEY....we just turned on...." or we just closed a circuit, the Control Module is notified....that is ANALOG.  Like closing a switch.  THEN, the control module sends a signal to the Thermostat.....WE NEED COOLING...  The Thermostat "verifies" and then says...  OK.....here is your TURN ON SIGNAL.  Every signal going up and down or back and forth on the single pair of MPX wires....is a DIGITAL ONE.  It is NOT ANALOG....

NOW....  Microair just "cracked" the code.  They made an exact COPY of the codes.  They know every code that the Dometic Thermostat has internally....that includes the outgoing as well as the incoming.  SO....then, they designed or copied or duplicated or whatever.....the Dometic Thermostat.  THEN, they added the features.

They are smart folks.....and Dometic probably doesn't like them...  BUT, when it comes to helping out a member.  THEY ARE POWERLESS or perhaps CLUELESS.  They can NOT tell you....and they, twice, stated that in a phone conversation....TWO SEPARATE TECHS....  They depend on the Dometic CCC (the original MPX system) or the CCC2 for the NEW Penguin II MPX codes to work.  If there is a lack of signal or a defective component....like a cable or a control module....then they are totally OUT OF IT.  We have had repeated cases where there was an issue.  Then the members called Microair.  The first response....if still in warranty....we'll ship you a new one.

One member was a bit "frustrated" as the lack of knowledge of Microair.  He posted and we walked him through testing and swapping the control modules.  TURNS OUT....it was a faulty FRONT Zone 1 Module.  Otherwise, when he got his NEW (maybe refurbished) thermostat....NO JOY.  He ordered a new unit....swapped it out....set the DIPS and all was well and his OLD Micrair work worked.

WE or I....as I have been called out....brusquely... am NOT a Microair HATER.  We solve problems.  NOW....as to REV...  GOOD LUCK.  The BULK of the RV techs know little about Microair.  That is a fact.  They know very little about the Dometic.  OTHER THAN the basics...which we KNOW.  They test and swap and call Dometic... What is the FIRST THING THAT DOMETIC ASKS...  Does this system have a Dometic CCC or CCC2 Thermostat?  IF NO....then they are really not very helpful....  WHY....obvious.  YES, they will tell the techs to swap and do all the things that we do.  There is NO MAGIC HERE.  You have to test and verify and make sure that the cables or the connections are OK.  If the Thermostat (either Dometic or Microair) doesn't work....then they (Dometic) will say... REPLACE with a new one.  OPPS....there are NOT any new ones....as you found out.

Bottom line....and I apologize for the depth of this response.  The Dometic is a very sophisticated system.  It depends on all components and connections and inputs working.  UNFORTUNATELY....if it is the 5 Button Thermostat....then there are few options.  Ordering a NEW Microair....without testing the the old thermostat on all three units...and having voltage to each is the ONLY way to verify.  OK...if it fails on Zone 2....then  the ODDS ARE...it MIGHT be the Thermostat.

BUT...  until all the troubleshooting is done....then that is the time to invest in a new thermostat....and Microair is the only game in town.  BUT, finding a good tech....that even knows how the Domeitc works is hard....much less how the Microair is supposed to work and how to test and verify.

THAT IS THE REAL WORLD.

I personally do FEEL YOUR PAIN...but after maybe 100 of these events....dating back over 15 years.....the same things apply.  The Connections are first.  Lack (cut wire or fuse) of 12 VDC is next. Then most like the thermostat....but it COULD and has been more times than one would expect....the Control board.

Good Luck...  and keep posting....but this post sums up the entire Dometic HVAC system....which may be presented at the Gathering...  

Thanks for reading.....

[woodylmiller]

Thanks Tom.  Plenty to think about.  And as stated, it's complicated.  Add to that is the constant up and down from the roof.  Got all returns exposed with all the dangles.  All couplings replaced.  All connections cleaned and worked back in and out.  12vdc at the thermostat, but no back light or display.  So when first attempting to check to make sure the A/C's were working, zone 1 came on with no issue.  Moving to zone 2 and nothing, no display but the back light was on.  So went to work cleaning all connections.  Went to thermostat and now I have nothing, zone 1 no longer there along with the other 3.  No Display, no back light.  But 12vdc present, as well as about 4vdc at the thermostat plug.  A/C control fuse, good.  All 3 amp fuses in the units check good.  I have not checked for 12vdc at the control boards in the units; back on the roof I go today to check that.  If I follow correctly then if the control boards have 12vdc then, the connections are good, then another head scratcher will come to be.

One thing I noticed, and I don't think it's the problem since the system had worked without issue until now.  The RJ connectors on the roof did not always match the color code next to it.  Copper is copper and insulation color doesn't matter.  HOWEVER I MATCHED the existing plug color cord on the ends that I replaced.  So the fact the Monaco didn't seem to care sometimes about how things went.  I had one the units were they, Monaco, did not plumb my aux air pump for leveling correctly which caused the pump to run all the time.  The fix by previous owner or repair shop was simply to removed the fuse to the pump.  Fortunately I have data cable tester so that will be another thing to check, I haven't to this point since I copied the color code on the existing plug (I was wearing a 30x magnifier when checking and repeating color code).  I only had to replace 3 of the RJ plugs, all 6p4c.

So today I check for the 12vdc on the boards and go from there.  Also, I agree with about MicroAir who claim to be plug and play, which rarely happens in my case.

I have no respect for the "new" REV.  I will reserve that feeling for the guys in Coburg who to date have been the only shop to work on and fix the dreaded Kongsberg MPX "brain" for us.  EVERY shop that I tried, including M&M in Ohio(?), said the system could not be fixed.  Are control boards still available for these units?  

One last thing; the 12vdc voltage source.  My schematics for the system is a little confusing.  The A/C control circuit located in the MPX board in the rear wardrobe is, that my 12vdc for the units?  The fuse is clearly marked "A/C Control" and the fuse is good.  As some have said Monaco chose different places to get the 12vdc.  I like a good challenge but due to the weather changing I'm up against the clock.  And that usually means spending money for tech's when I can usually do all this stuff myself given enough time.  I've got a roll of 4c telephone cable around somewhere in my "stack of stuff", and CAT cable does not contain red, black, green and yellow conductors, not that color matters as long as continuity remains good.  But I might just pull in all new cable while I have every thing topside and inside opened up.  And I can just here a tech somewhere saying the colors of the CAT conductors are wrong, they need to be the RBGY colors.  WRONG shop.

Thanks again, good conversation and very helpful,

Woody Miller

09 Dynasty

[Tom Cherry]

2 minutes ago, woodylmiller said:

Thanks Tom.  Plenty to think about.  And as stated, it's complicated.  Add to that is the constant up and down from the roof.  Got all returns exposed with all the dangles.  All couplings replaced.  All connections cleaned and worked back in and out.  12vdc at the thermostat, but no back light or display.  So when first attempting to check to make sure the A/C's were working, zone 1 came on with no issue.  Moving to zone 2 and nothing, no display but the back light was on.  So went to work cleaning all connections.  Went to thermostat and now I have nothing, zone 1 no longer there along with the other 3.  No Display, no back light.  But 12vdc present, as well as about 4vdc at the thermostat plug.  A/C control fuse, good.  All 3 amp fuses in the units check good.  I have not checked for 12vdc at the control boards in the units; back on the roof I go today to check that.  If I follow correctly then if the control boards have 12vdc then, the connections are good, then another head scratcher will come to be.

One thing I noticed, and I don't think it's the problem since the system had worked without issue until now.  The RJ connectors on the roof did not always match the color code next to it.  Copper is copper and insulation color doesn't matter.  HOWEVER I MATCHED the existing plug color cord on the ends that I replaced.  So the fact the Monaco didn't seem to care sometimes about how things went.  I had one the units were they, Monaco, did not plumb my aux air pump for leveling correctly which caused the pump to run all the time.  The fix by previous owner or repair shop was simply to removed the fuse to the pump.  Fortunately I have data cable tester so that will be another thing to check, I haven't to this point since I copied the color code on the existing plug (I was wearing a 30x magnifier when checking and repeating color code).  I only had to replace 3 of the RJ plugs, all 6p4c.

So today I check for the 12vdc on the boards and go from there.  Also, I agree with about MicroAir who claim to be plug and play, which rarely happens in my case.

I have no respect for the "new" REV.  I will reserve that feeling for the guys in Coburg who to date have been the only shop to work on and fix the dreaded Kongsberg MPX "brain" for us.  EVERY shop that I tried, including M&M in Ohio(?), said the system could not be fixed.  Are control boards still available for these units?  

One last thing; the 12vdc voltage source.  My schematics for the system is a little confusing.  The A/C control circuit located in the MPX board in the rear wardrobe is, that my 12vdc for the units?  The fuse is clearly marked "A/C Control" and the fuse is good.  As some have said Monaco chose different places to get the 12vdc.  I like a good challenge but due to the weather changing I'm up against the clock.  And that usually means spending money for tech's when I can usually do all this stuff myself given enough time.  I've got a roll of 4c telephone cable around somewhere in my "stack of stuff", and CAT cable does not contain red, black, green and yellow conductors, not that color matters as long as continuity remains good.  But I might just pull in all new cable while I have every thing topside and inside opened up.  And I can just here a tech somewhere saying the colors of the CAT conductors are wrong, they need to be the RBGY colors.  WRONG shop.

Thanks again, good conversation and very helpful,

Woody Miller

09 Dynasty

Wow….you are out typing me…

First.  There is, as you probably know, the Dometic Data Cable Color Code in their Penguin Installation manual.  It is the SAME for the CCC as the CCC2.  

I’d make up one short cable….say 24”.  Should match the Dometic spec.  Then…take that cable and my DVOM and go topside.

Carry alcohol and Q-Tips and CRC ELECTRONICS cleaner…not ELECTRICAL.  Clean the female RJ11 on the board…  Test the 12 VDC terminals for the INCOMING voltage.  Plug in yiur TEST Cord.  Forget there is a MPX pair….if you have 12VDC…on the PROPER pair (use DVOM) on the incoming….and the two “power” leads for the Thermostat….  THEN use your known GOOD test jumper or 24” freshly made….plug in the Thermostat to that one and into one of the RJ11 females.  Reboot….  Should have FF and the only zone showing (assuming you have unhooked the two “top to plenum” danglers) will be the ZONE number.  You should then be able to scroll through MODE.  If OK….then….unplug the extension or test….repeat on the OTHER Female.

OBVIOUSLY, I assumed you have cleaned the top side RJ11 Female connectors.  

THEN….repeat on Zone 2 and Zone 3.  NOW, you KNOW that the control modules are “clean” and the thermostat works.  The “erratic” results you reported are not uncommon and are usually symptoms of a POOR connection,

NOW…since you don’t know what or why the system was worked on….   Clean the female terminals in the “INLINE” connectors.  Now TEST THEM.  Using your DVOM in Continuity….with the BEEP…put the connector in front of you.  The female end should be pointed SIDE to SIDE….as in LEFT and RIGHT.  It HELPS to have a helper or you can use a vise.  Put the DVOM lead on the wire or contact CLOSEST to you….and then check for continuity on the wire or lead on the OTHER side.  The PROPER connector is “STRAIGHT THROUGH”…so if the closest wire or terminal is “1”….and the next are 2, 3, and 4….  Then using that same nomenclature on the opposite or other end….1 goes to 1 and 4 goes to 4.  I just got in replacements and verified them….did NOT fool with 2 or 3…

NOW….known CORRECT Connectors.  Are the DANGLERS color coded correctly per Dometic….

When all is checked out…then INSIDE, on either dangler….the Thermostat should work….assuming that the power pair was correct topside and there was 12 VDC to every module,

As to the MPX or the Intellitec system.  The Control Module power comes off a HOUSE FUSE…..it is NOT, but check your prints, connected or part of the Intellitec MPX.  YES….there IS an interface for “HEAT” where you have the Intellitec MPX controlling the blowers, via modules, on the Aquahot….BUT the HP or AC is NOT even remotely connected or impacted.

YES…Monaco did a POOR JOB, sometimes….on labeling the Dometic 12VDC Control circuit…but it is only ONE FUSE…and it is ONLY in the House Distribution Fuse panel….NOT on the Intellitec MPX “modules”.

Thats the drill….good luck….

 

 

[Ivan K]

Maybe it was already mentioned but make sure the thermostat slider switch solder connections are reliable, the switch itself is trouble waiting to happen the way it was mounted.

[Tom Cherry]

15 minutes ago, Ivan K said:

Maybe it was already mentioned but make sure the thermostat slider switch solder connections are reliable, the switch itself is trouble waiting to happen the way it was mounted.

EXCELLENT POINT.  Try spraying a little contact cleaner under or on the switch and cycling.  Based on the “attempts”, and the erratic results….a faulty power switch could be the culprit.  
 

Thanks…

[woodylmiller]

OK, all three units have 10vdc at the board.  Tried the thermostat on each of the danglers, still nothing.  Strangely enough when disconnecting the danglers on 1 and 2 I hear what sounds like a relay either latching or making momentary contact.  I can not find where the sound is coming from.  It is somewhere on curb side on the inside of the coach, not down in a bay, but maybe, who knows.  Now the rear unit does not do this and only one of the dangles is mated to a coupler and a dangler going nowhere.

So if I am following continuity checking on the board and the two RJ jacks.  Pin #1 equals pin #1 on the adjacent jack.  I'm going to need to order some more of the RJ6p4c connectors.  The only marking I can see on the cables is a dark grey/black cable goes to the units and beige cable in the plenum.  Time to go through my stack of stuff and find my phone cable so the colors match exactly as the data/factory cables.  Was using CAT cable for my cheater, so just to avoid any confusion I'll make a test cord using actual phone cables.  They certainly did no one any favors the way and location of the control board, I'll tell you that.  PITA getting out and back in.

I'll give that switch on the thermostat a good dose of electronic cleaner, cause that could certainly explain things.

Thanks,

Woody Miller

09 Dynasty

[jacwjames]

This is not a standard phone cable, the ends are reversed.

[woodylmiller]

Man is this a little confusing keeping track of the checks and cross checks.  So, I have 13+vdc BEFORE going to the unit, at the unit I have 10vdc.  I wouldn't think that is my problem with a 3vdc drop at the board.  Here is my next question; the RJ jacks on the control board are redundant in terms of polarity.  To simplify the two cables going to the board are then "T'ed" with leg of the "T" feeding the board and the two cables simply pass through maintaining color or position to position.  As you describe 1 to 1, 2 to 2 and so on.  For example the black to black should be 0 ohms.  I think that's correct but please advise if not.  Really parallel conductors from 1 to 2 and 3.  I sure hope zone 4 is not the problem since I have no idea where to look for that.

I did spray electronic cleaner on the switch, but to no avail.

Woody Miller

09 Dynasty 

[Tom Cherry]

9 minutes ago, woodylmiller said:

Man is this a little confusing keeping track of the checks and cross checks.  So, I have 13+vdc BEFORE going to the unit, at the unit I have 10vdc.  I wouldn't think that is my problem with a 3vdc drop at the board.  Here is my next question; the RJ jacks on the control board are redundant in terms of polarity.  To simplify the two cables going to the board are then "T'ed" with leg of the "T" feeding the board and the two cables simply pass through maintaining color or position to position.  As you describe 1 to 1, 2 to 2 and so on.  For example the black to black should be 0 ohms.  I think that's correct but please advise if not.  Really parallel conductors from 1 to 2 and 3.  I sure hope zone 4 is not the problem since I have no idea where to look for that.

I did spray electronic cleaner on the switch, but to no avail.

Woody Miller

09 Dynasty 

OK….YES.  The two Female RJ11 are like a “terminal” strip.  The Control modules are attached….

Think of the circuit from a “switch” concept.  The Data Com cable has 4 conductors….  So, it you laid them out…..the Data Com line is like 4 “WIRES”……it just runs from the Thermostat to the last unit.  Everywhere there are the TWO RJ11’s….that is just a Junction.  So….you have a device (Control Module) that taps or attaches to the circuit there.  The Data Com cables are always connected.   Yes….they are in parallel.

NOW….just to be EVIL…..you have the SAME system on the Intellitec MPX. There is a 3 conductor harness or bundle that runs from the CPU all the way down one side, crosses over…and comes or goes up the other.  It terminates where the last switch is.  Everywhere there is a “lighted” switch, there is a single 3 wire connector.  That switch plugs into the MPX data buss.  So each switch is in parallel.  When a single switch is pushed….it send out (Hexadecimal I THINK) a code.  Module Alpha code (say D through J).  Then it sends out a circuit number…1 - 10 OR 0 - 9…. I think it is 1 - 10….  For example….there is a Relay Output for ON and OFF…. Typically the exhaust fans and the pump and the fluorescent.  NON DIMMING.  If the Pump is on that Module…say “G” and the circuit is “7”.  Then EVERY PUMP SWITCH is coded G-7.  There are 5, I think, in your MH.  So all FIVE switches are programmed G-7.  Push any one….and G-7 goes down the MPX data buss.  The CPU gets that code.  It then tells Module G and Circuit 7 to “toggle”.  If ON….turn OFF.  If OFF….turn on.

This is exactly HOW the HVAC works.  The Thermostat “knows” after a successful reboot, how many Modules are recognized….or Zone 1 - 4.  Then based on digital signals from each Module….it tells the Thermostat what is happening.  If the remote temp sensor is ON in Zone 3….that means…..TURN ON SOMETHING…..and the coded digital MPX signal is interpreted by the Thermostat and it sends out an instruction.

Thats IT…

[woodylmiller]

I believe I have found the problem, at least one of them, and hopefully the only problem.  To sum things up, I disconnected all the connections, all couplers and danglers.  Removed all the RJ plugs on the control boards.  My front A/C, zone 1, is where it all begins.  Power from a 2 amp circuit located in the rear wardrobe closet is connected to the red and black wires that come down from the roof.  There are 6 wires, danglers from P6 on the control board.  This connection is the ONLY source for the 12vdc power for the control boards.  Power and data then go from unit to unit via the RJ connections, two on each board.  Power at the first connection was measured at 13.8vdc.  But measuring the voltage on the control board was just 10vdc.  I connected a jumper for power from zone 1 to zone 3 to begin, and all other connections disconnected.  All test were done by feeding the input voltage to the board via the red and black dangler wires from the roof.  Voltage at the RJ jack was measured at 12.4vdc.  That would mean that there is circuitry on the board that uses some power before being present at the RJ jack.  Now for some strange reason when 120vac is applied to the unit the voltage at the RJ jack then measures 13.47vdc.  I had my meter connected to one of the RJ jacks and the thermostat was connected to the other RJ jack.  My thermostat came to life, rebooted, got the FF and then ran the fan to see if all is well.  This was repeated for all three units and all responded the same.

So, thermostat is good, the unit functions.  So on to the next tests.  Using my cable tester I started to identify each of the data/power cables in the ceiling.  Then I located the problem.  The cable from zone 3 to zone 2 is shorted.  Not a dead short, but just enough to bleed off about 4vdc and most likely some of the voltage got onto the data conductors, hence the "EE" message on the thermostat.  A dead short to ground would have blown the 2 amp fuse.

The thermostat is good and the units respond to it.  Now to fix the bad cable.  Discussed with Tom how to do that and I think the easiest will be to install a weather/UV resistant wire mold from A/C 3 to 2, surface mounted.  The interior cables will not budge to pull in a new cable that way.  

This was a challenge to get to this point and I'd like to thank Tom Cherry and others for their help and input.  After two days of testing, reading and listening I was able to get to the bottom of my problem.  I started off thinking it must be the thermostat.  After all, I had 12vdc at the thermostat, so without a backlight or any data on screen I thought "what else could it be?".  Well most likely a staple leg punctured the cable and finally through vibration maybe, the data and power conductors decided to shake hands and bring my system down.

I used a multi-meter for voltage and an Ethernet/PoE cable tester for all my tests.  Took some time and plenty of head scratching.  And it helped considerably that Monaco had labeled the A/C control circuit so that I didn't have to search out that part of the system.  I'd like to add that my background is 45 years as an electrician so that helped with understanding circuitry and logic.  But with the right tools for testing, and input from members here, it's doable.  

Thanks again to all,

Woody Miller

09 Dynasty

[DBRV.0]

1 hour ago, woodylmiller said:

Discussed with Tom how to do that and I think the easiest will be to install a weather/UV resistant wire mold from A/C 3 to 2, surface mounted.

Good to hear that you have diagnosed the probable root of your problem!

I believe I am accurate in saying that you have 4 Zones, just like I do.  Your Zones 1,2,3 have one rooftop A/C each, Zone 4 is heat-only for the rear bathroom.  You know that the three A/C units each have their own control board.  Be aware that there is a fourth control board connected via RJ11, between A/C 2 and A/C 3.  That control board is "dip switched" as Zone 4.  What I am saying is that if you connect Zone 3 directly to Zone 2, you will bypass Zone 4's control board.  In other words, the OEM RJ11 sequence is: Thermostat -to- A/C 1 -to- A/C 2 -to- Zone 4 -to- A/C 3.

One option that comes to mind is to go ahead and connect A/C 2 to A/C 3, and substitute the unused dangling RJ11 at A/C 3 for the RJ11 that originally comes from Zone 4 control board.  That way, communication gets back to Zone 4.  If you have a partially shorted wire, this still may not work because the bad RJ11 is still present.

Another, preferred, option I can think if is to one-by-one, replace the RJ11 connectors that lie between A/C 2 and A/C 3 with new connectors.  Assume the wire itself is good.  It is not uncommon for a connector to corrode internally or to have a flaw.

The final option that comes to mind would be to locate the Zone 4 control board, and work that into your solution.  IIRC, Tom says is not sure where it physically resides.  My best guess would be inside the intake plenums of either A/C 2 or A/C 3.

Best wishes with your final solution.

- Jeff

[Frank McElroy]

The first 3 zones MUST be rooftop AC unit.  Any additional heat only circuit board zones MUST be setup as zone 4 - after the AC zones.

So, lets say you have a center bath coach.  Logic would say then you have the front AC as zone 1, the center AC as zone 2, the center bath as zone 3 and the rear bedroom AC as zone 4.  NO, THAT WOULD BE WRONG.  The rear AC MUST be programmed as zone 3 and the center hidden bath zone must be set as zone 4.  That's a requirement of the 5 button remote.  All AC units MUST be before any non AC heat (furnace) only remote control boards.

 

[Tom Cherry]

9 hours ago, Frank McElroy said:

The first 3 zones MUST be rooftop AC unit.  Any additional heat only circuit board zones MUST be setup as zone 4 - after the AC zones.

So, lets say you have a center bath coach.  Logic would say then you have the front AC as zone 1, the center AC as zone 2, the center bath as zone 3 and the rear bedroom AC as zone 4.  NO, THAT WOULD BE WRONG.  The rear AC MUST be programmed as zone 3 and the center hidden bath zone must be set as zone 4.  That's a requirement of the 5 button remote.  All AC units MUST be before any non AC heat (furnace) only remote control boards.

 

WOW... I did NOT KNOW that.  Thanks.  Obviously the "smarty pants" thermostat....ain't as smart as he (she or it?) thinks it is....

[Tom Cherry]

13 hours ago, woodylmiller said:

I believe I have found the problem, at least one of them, and hopefully the only problem.  To sum things up, I disconnected all the connections, all couplers and danglers.  Removed all the RJ plugs on the control boards.  My front A/C, zone 1, is where it all begins.  Power from a 2 amp circuit located in the rear wardrobe closet is connected to the red and black wires that come down from the roof.  There are 6 wires, danglers from P6 on the control board.  This connection is the ONLY source for the 12vdc power for the control boards.  Power and data then go from unit to unit via the RJ connections, two on each board.  Power at the first connection was measured at 13.8vdc.  But measuring the voltage on the control board was just 10vdc.  I connected a jumper for power from zone 1 to zone 3 to begin, and all other connections disconnected.  All test were done by feeding the input voltage to the board via the red and black dangler wires from the roof.  Voltage at the RJ jack was measured at 12.4vdc.  That would mean that there is circuitry on the board that uses some power before being present at the RJ jack.  Now for some strange reason when 120vac is applied to the unit the voltage at the RJ jack then measures 13.47vdc.  I had my meter connected to one of the RJ jacks and the thermostat was connected to the other RJ jack.  My thermostat came to life, rebooted, got the FF and then ran the fan to see if all is well.  This was repeated for all three units and all responded the same.

So, thermostat is good, the unit functions.  So on to the next tests.  Using my cable tester I started to identify each of the data/power cables in the ceiling.  Then I located the problem.  The cable from zone 3 to zone 2 is shorted.  Not a dead short, but just enough to bleed off about 4vdc and most likely some of the voltage got onto the data conductors, hence the "EE" message on the thermostat.  A dead short to ground would have blown the 2 amp fuse.

The thermostat is good and the units respond to it.  Now to fix the bad cable.  Discussed with Tom how to do that and I think the easiest will be to install a weather/UV resistant wire mold from A/C 3 to 2, surface mounted.  The interior cables will not budge to pull in a new cable that way.  

This was a challenge to get to this point and I'd like to thank Tom Cherry and others for their help and input.  After two days of testing, reading and listening I was able to get to the bottom of my problem.  I started off thinking it must be the thermostat.  After all, I had 12vdc at the thermostat, so without a backlight or any data on screen I thought "what else could it be?".  Well most likely a staple leg punctured the cable and finally through vibration maybe, the data and power conductors decided to shake hands and bring my system down.

I used a multi-meter for voltage and an Ethernet/PoE cable tester for all my tests.  Took some time and plenty of head scratching.  And it helped considerably that Monaco had labeled the A/C control circuit so that I didn't have to search out that part of the system.  I'd like to add that my background is 45 years as an electrician so that helped with understanding circuitry and logic.  But with the right tools for testing, and input from members here, it's doable.  

Thanks again to all,

Woody Miller

09 Dynasty

WOODY....

I had been doing a response with some "INFO" or explanation to teach or help other members, if interested...  and THEN...took a break.  IT JUST HIT ME.  I have PM's you.

YES... you DO have a short or that is what your tester is telling you.

BUT, thanks to @DBRV.0 or Jeff's Block Diagram.....the problem is NOT in the Zone 2 to Zone 3 Cable.  That cable does NOT EXIST.  The path is from Zone 2 to Zone 4....then from Zone 4 to Zone 3.  For those folks who "lost their playbill"....see the two below.  Jeff indicates....which I THINK...is true....that Zone 3 is at the END of the data buss....as in there is a "UNTERMINATED DANGLER".  His block matches the print....

I also contacted Frank and he advised that you will get "FALSE" readings if you test a cable that is plugged into another controller.  THUS, you have to disconnect the TWO cables (RJ11) from the Zone 4 controller.  THEN, with those two cables also DISCONNECTED from Zone 2 and Zone 3, respectively....you TEST THE CABLE.

You may NOT have a shorted or leg of a staple through one cable.  It may be an issue with the controller.  Frank will get back to you offline and tell you WHERE and HOW to get to the Zone 4 controller.  Based on what he said....your's is simple....as compared to what I would have to do....  Taking a panel out of a cabinet.

THAT'S IT...

Therefore, you need to go back to troubleshooting.  I have sent you a PM and copied Frank. Frank knows WHERE the hidden controller is and should be able to assist you in locating it.  THEN....keep testing.  Again....it goes back to the old MANTRA.  Keep troubleshooting, properly, until you locate the "source".  You're almost there....

Hope this helps.  You were ALMOST at the finish line....but it got moved.

Good luck...

[woodylmiller]

Well dang.  Good point.  Got the message from Frank.  I do have a removable panel below the TV in the living room which is on the other side of the 1/2 bath before the bedroom.  As I mentioned, I could hear a "noise" on the interior curb side, close where the TV is.  I could not actually figure out where the noise was coming from.  I'll try another test with what we call a "fox and hound" signal generator for tracing wires in a bundle where visual searching doesn't work.  Since the way the zones daisy chain this may not work, but I'll have to try.  The signal may be strong enough for the receiver to pick up the scent behind the walls.  Hey, would have been nice if Monaco had given an "as built" print with each coach.  Assuming you would never have a problem with the systems, hiding elements was not a good solution.  Keeps the service centers in business I guess.

Woody Miller

09 Dynasty

 

[Tom Cherry]

2 hours ago, woodylmiller said:

Well dang.  Good point.  Got the message from Frank.  I do have a removable panel below the TV in the living room which is on the other side of the 1/2 bath before the bedroom.  As I mentioned, I could hear a "noise" on the interior curb side, close where the TV is.  I could not actually figure out where the noise was coming from.  I'll try another test with what we call a "fox and hound" signal generator for tracing wires in a bundle where visual searching doesn't work.  Since the way the zones daisy chain this may not work, but I'll have to try.  The signal may be strong enough for the receiver to pick up the scent behind the walls.  Hey, would have been nice if Monaco had given an "as built" print with each coach.  Assuming you would never have a problem with the systems, hiding elements was not a good solution.  Keeps the service centers in business I guess.

Woody Miller

09 Dynasty

 

TEST THE TWO CABLES.  CLEAN the contacts on Zone 4.  Never know.  We HAVE had a Z4 failure…I THINK.  Thank Jeff for his drawing….and thank my wife for telling me to EAT BREAKFAST….  Then it hit me.  So far, you are ELIMINATING issues.  NOW….with the cables from Zones 2 & 3 plugged in….you SHOULD have board power…..it will NOT come from P6….according to Frank….so test the RJ11 pins.

Past that…..??  But cleaning the contacts there might do it,  BTW….you now know MORE that at least 25 or 50% of the “RV HVAC TECHS” do.

 

[woodylmiller]

Having so much fun I decided to open another can of worms.  I found zone 4.  Disconnected all interior data/power cables and verified routing.

T-stat to front A/C(zone 1), then cable goes to middle A/C,(zone 2), then cable goes to zone 4, (the hidden control board), then cable goes to rear A/C(zone 3).  All checked and double checked.  Tested cables, all of them at least 4 times with cable tester, all good, no shorts.  Previous thoughts about a short was actually the zone 4 being connected and my tester must have responded to that load as a short.

Checked, double checked, all the danglers.  No apparent damage.  So connected all couplings and RJ plugs to their jacks.  Plugged T-stat back in and attempted reboot.  Never got the FF reading.  The backlight is on, and zone 1 is showing, but none of the other zones.  More rebooting and still the same result.  Unable to reboot the T-stat.  I next turned on the 120vac to all three units.  Middle and rear A/C came on.  Yet zone 2 and zone 3 do not appear on the T-stat.  Nothing but zone 1 appears in the T-stat display, without doing any control of the zone 1.

So this is what I have now.  With the T-stat disconnected from the wall, no cable attached.  A/C zone 2 comes on.  A/C zone 3 comes on as soon as I turn the 120vac power on.  Zone 1, nothing.  The A/C are coming on immediately, like not going through the EMS were there would normally be a delay before start up.  I then disconnected all interior cables and at that point none of the A/C come on.

I did not mess with any settings on the control boards, never touched the dip switches.  The T-stat comes on to zone 1 as soon as I plug it in, but no control of the zone 1 A/C.  I can control zone 1 when isolating that unit by connecting only the T-stat to unit one with no other dangler connected, same as plugging straight into the control board from the roof location.  The A/C responds as it should going through the EMS with the delay start up.  With only zone 1 and T-stat connected the stat will reboot and give me the FF.  But still no zone 2,3 or 4 showing.

Not sure where to go to next.  Only thing I can think of now is getting the T-stat to reboot.  One other thing about the T-stat, as soon as I plug it in the light comes on and displays zone 1 even with the switch on the bottom in the "off" position.

Just when I think I'm finished, it pulls me back in.  LOL

Woody Miller

09 Dynasty