RoadTripper2084 Posted August 23 Share Posted August 23 (edited) Well in the vein of "there's always something" that needs attention on this old girl, my dash fan / blower decided to stop working last weekend. It had been working just fine/perfectly previously, but when I started the coach to drive home from Banff it simply did not work. However, the air flow position adjust *does* still work, at least I can hear it moving when I change the setting (with the engine off). Reading through the usual suspects here, I ordered and installed a new resistor pack. No dice. I tested the resistor pack connector, and even with the resistor pack installed, when I put the red end of my meter on the back of a connector on the pack, and the black on the chassis ground, they all read 12.5v. So the good news is I have power, the bad news is none of the voltages changed at all regardless of what fan speed setting I selected. At this point I'm confused on the theory behind the resistor pack? It doesn't lower the voltage to the fan? It just adds resistance which results in lower amperage to the fan? In any case, I'm lost as to what to look for next. The fan itself was working fine and wasn't making any strange sounds or anything prior to deciding to stop working altogether. Dynasty 1997 AC Wiring.pdf Edited August 23 by RoadTripper2084 Attached wiring diagram Link to comment Share on other sites More sharing options...
Tom Cherry Posted August 23 Share Posted August 23 1 hour ago, RoadTripper2084 said: Well in the vein of "there's always something" that needs attention on this old girl, my dash fan / blower decided to stop working last weekend. It had been working just fine/perfectly previously, but when I started the coach to drive home from Banff it simply did not work. However, the air flow position adjust *does* still work, at least I can hear it moving when I change the setting (with the engine off). Reading through the usual suspects here, I ordered and installed a new resistor pack. No dice. I tested the resistor pack connector, and even with the resistor pack installed, when I put the red end of my meter on the back of a connector on the pack, and the black on the chassis ground, they all read 12.5v. So the good news is I have power, the bad news is none of the voltages changed at all regardless of what fan speed setting I selected. At this point I'm confused on the theory behind the resistor pack? It doesn't lower the voltage to the fan? It just adds resistance which results in lower amperage to the fan? In any case, I'm lost as to what to look for next. The fan itself was working fine and wasn't making any strange sounds or anything prior to deciding to stop working altogether. Dynasty 1997 AC Wiring.pdf 130.47 kB · 0 downloads The THEORY behind the RESISTOR....there is NO Resistance and THEN the FAN BLOWS FULL SPEED. Then you add in resistance. It is a SERIES add. You add in X ohms....that slows it down.... the Resistor, of COURSE, gets hot. That is why it is the AIRFLOW stream. Then you turn it down another NOTCH. You then add in another X ohms of resistance....and they are in series. That slows down the fan speed. SO....HIGH is NO resistance. Then Resistor 1 goes to MEDIUM. Then Resistor 2 to LOW. If you have a Four Speed fan speed.... DON'T hold me to that....then there has to be THREE resistors in the pack....and finally for LOW, all three are in SERIES I would look at the CONTROL Harness. The theory is that there are TWO WIRES....HOT and GROUND. Then, the Fan Speed control dials them IN. If you use a FULL 12 VDC to the Fan Motor....it should RUN at FULL SPEED. BUT, then you have to add in the Resistors. The switch does that. You CAN use alligator clips or pins (Small Nails) in the harness. If you add in ALL the resistors....as in SERIES STRING THEM....then the fan should run at LOW. That's, in THEORY how it works... so all the Fan Control does is do the SWITCHING or add or subtract a resistor in the pack.. Hope this helps.... DON'T beat yourself up....many folks find this sort of confusing.....and It takes a while for the logic sink in.... Link to comment Share on other sites More sharing options...
Rikadoo Posted August 23 Share Posted August 23 So it SOUNDS like your measuring at the resistor, measure at the motor, measure to wire going to it, do you have voltage y/n, if you have voltage, now probe the case or the grounddo you have voltage… yes then you lost your case ground, no the motor 💩 the bed if when you probe the wire going to the fan an you hav 0 volts then start looking at ANY connectors between the resistor an the motor, separate the two and then look to see if there’s corrosion or if one of the pins has pushed out 1 Link to comment Share on other sites More sharing options...
Benjamin Posted August 23 Share Posted August 23 Yes, the resistor is not lowering the voltage because the fan is not drawing any amps. Either there's a bad connection between the resistor and the fan, fan and ground, or the fan motor itself is burned up, or has a bad connection inside. Link to comment Share on other sites More sharing options...
RoadTripper2084 Posted August 23 Author Share Posted August 23 Thanks for the responses everyone. So it sounds like I need to access the motor and related wiring connection next. That is located under the PS dash, requiring removal of the dash to access, is that correct? Link to comment Share on other sites More sharing options...
John M Posted August 24 Share Posted August 24 On 8/22/2024 at 6:36 PM, RoadTripper2084 said: Well in the vein of "there's always something" that needs attention on this old girl, my dash fan / blower decided to stop working last weekend. It had been working just fine/perfectly previously, but when I started the coach to drive home from Banff it simply did not work. However, the air flow position adjust *does* still work, at least I can hear it moving when I change the setting (with the engine off). Reading through the usual suspects here, I ordered and installed a new resistor pack. No dice. I tested the resistor pack connector, and even with the resistor pack installed, when I put the red end of my meter on the back of a connector on the pack, and the black on the chassis ground, they all read 12.5v. So the good news is I have power, the bad news is none of the voltages changed at all regardless of what fan speed setting I selected. At this point I'm confused on the theory behind the resistor pack? It doesn't lower the voltage to the fan? It just adds resistance which results in lower amperage to the fan? In any case, I'm lost as to what to look for next. The fan itself was working fine and wasn't making any strange sounds or anything prior to deciding to stop working altogether. Dynasty 1997 AC Wiring.pdf 130.47 kB · 1 download This sounds to me as if you have lost your ground from the motor. I once replaced the blower motor and it worked fine for a year and then stopped working. I found that when I had plugged the ground wire onto the tab on the motor I missed the mark. Instead of properly inserting the spade into the lug I pushed the spade between the lid and the plastic cover. It finally worked free and was just sitting on top of the spade. 1 Link to comment Share on other sites More sharing options...
RoadTripper2084 Posted August 27 Author Share Posted August 27 On 8/23/2024 at 8:43 AM, RoadTripper2084 said: That is located under the PS dash, requiring removal of the dash to access, is that correct? Can anyone confirm whereabouts I need to look for the dash blower motor and related wiring? I have some pictures from under my dash when I had it all opened up to fix the wiring short issue but nothing jumps out as clearly being the blower for some reason. Is it one of these boxes on the PS side of the dash? Link to comment Share on other sites More sharing options...
Benjamin Posted August 27 Share Posted August 27 My 95 Safari it would be on the right side of the metal box, but mine is not identical. Is there a round motor housing sticking forward or backward from that "split" housing on the right side? Link to comment Share on other sites More sharing options...
RoadTripper2084 Posted August 27 Author Share Posted August 27 3 hours ago, Benjamin said: My 95 Safari it would be on the right side of the metal box, but mine is not identical. Is there a round motor housing sticking forward or backward from that "split" housing on the right side? Unfortunately, this is the only pic I have under the dash in that area. I'm just trying to be certain that I need to remove the dash again to get at the motor before I do so. Link to comment Share on other sites More sharing options...
Benjamin Posted August 27 Share Posted August 27 I don't SEE any obvious wires going to the area where the blower motor should be. I'm 99% sure the motor is in that split housing on the right, but you could also check the blower motor speed selector switch. The switch sends voltage to the resistor(s) that controls the blower motor lower speeds, that voltage comes back to the switch and then out separate wire to the motor, high speed bypasses the resistor for full voltage. On my safari, the motor wires are black with a white spiral stripe for hot, and a white for "neutral/ground", the switch to resistor wires are all colored, red etc. If you turn the speed switch off, then there should be only one supply wire with 12v, then if there's a group of colored wires bundled, those would be the resistor, and the last one would be the hot to the motor, if you can follow that, the ground may be bundled and you could test there. Next would be pulling the dash to get at the motor. 1 Link to comment Share on other sites More sharing options...
dandick66 Posted August 28 Share Posted August 28 15 hours ago, RoadTripper2084 said: Unfortunately, this is the only pic I have under the dash in that area. I'm just trying to be certain that I need to remove the dash again to get at the motor before I do so. My blower motor is accessible from the front. Have you checked that for access? 1 Link to comment Share on other sites More sharing options...
RoadTripper2084 Posted August 28 Author Share Posted August 28 3 hours ago, dandick66 said: My blower motor is accessible from the front. Have you checked that for access? From the front as in in the front generator compartment opening / in front of the firewall? Link to comment Share on other sites More sharing options...
dandick66 Posted August 28 Share Posted August 28 Yes, on the firewall area in the generator compartment Link to comment Share on other sites More sharing options...
RoadTripper2084 Posted August 28 Author Share Posted August 28 32 minutes ago, dandick66 said: Yes, on the firewall area in the generator compartment Wouldn't that be excellent! I didn't see it popping out at me when I was in there but I'll take a closer look for sure. Thx. Link to comment Share on other sites More sharing options...
RoadTripper2084 Posted September 7 Author Share Posted September 7 (edited) Okay, I was able to poke around a bit and take some pictures. So far as I can tell the fan motor must be mounted inside a large metal box that itself is inside the PS dash compartment. This metal box has the ventilation hoses coming out of it, and seems to connect to a large plastic box that extends to the outside of the firewall, which has the resistor pack mounted to it and also some heater or perhaps A/C coils. The ventilation hoses for the windshield defrost exit the large plastic box mounted outside the firewall in the generator compartment: Can anyone confirm that I need to take this metal box under the PS dash apart to access the blower fan motor? ------- In addition, I found this motor under the front centre outside the firewall, in the generator compartment. Does anyone know what this is for? Edited September 7 by RoadTripper2084 Link to comment Share on other sites More sharing options...
Benjamin Posted September 7 Share Posted September 7 The motor pictured is the windshield wiper motor. In your first pic, I see the coolant hoses going to the heater core, and some A/C parts, look to the left of there for the motor wiring harness. In your pic on the Aug 27 post, the blower is inside the split housing on the right, so if the motor accessible from the front, it will be on the other side of that portion. You may not need to access the motor if you can access the closest connector in the wiring harness and power the motor from there, if it still won't run, then you need to access it. 1 Link to comment Share on other sites More sharing options...
RoadTripper2084 Posted September 7 Author Share Posted September 7 6 hours ago, Benjamin said: The motor pictured is the windshield wiper motor. In your first pic, I see the coolant hoses going to the heater core, and some A/C parts, look to the left of there for the motor wiring harness. In your pic on the Aug 27 post, the blower is inside the split housing on the right, so if the motor accessible from the front, it will be on the other side of that portion. You may not need to access the motor if you can access the closest connector in the wiring harness and power the motor from there, if it still won't run, then you need to access it. Of course it's the wiper motor, if I had looked at what was attached to it a little closer I'd have realized that. Doh! So the blower motor is inside this black component circled in red? Link to comment Share on other sites More sharing options...
Benjamin Posted September 8 Share Posted September 8 That's my guess, it looks round and feeds into the rest of the air distribution ductwork. The blower is inside that, the motor will be sticking out the front or back. If there's no wires and motor visible under that flex duct, then it should be visible in the front. 1 Link to comment Share on other sites More sharing options...
John M Posted September 8 Share Posted September 8 I have a 2000 Dynasty and had to replace the fan motor. In the picture where your leg is showing the motor is just about directly forward of your leg about a foot off the floor. I had to remove the center console and remove lots of screws to open up the dash to get inside. When you get in there you’ll see the motor attached to a metal housing. I think I have the part number from Orilies auto parts. 6 years ago it was about $20 plus two days labor. If I have the number I’ll post it tomorrow afternoon sometime. It was a tuff job but after you get to it, they change out is simple. When you get the motor, the squirrel cage should come with it. Look at the new one very closely because a friend of mine did this job and the first motor was backwards and the fins on the squirrel cage will be reversed. Take the old one with you to compare. 2 Link to comment Share on other sites More sharing options...
dandick66 Posted September 8 Share Posted September 8 Before you try to pull the motor see if you can find the wire connector going to it. It should be pretty close to the housing. Disconnect the motor and run a 12 volt jumper to it. If the motor spins, then you know your problem is upstream. 2 Link to comment Share on other sites More sharing options...
Benjamin Posted September 8 Share Posted September 8 Also check the ground from the connector. My ground is a flimsy clip on one of the mounting screws. Supply ground and hot, or check connector for hot and ground with fan "ON" "high". 1 Link to comment Share on other sites More sharing options...
RoadTripper2084 Posted September 8 Author Share Posted September 8 So I checked the power + ground wires at the motor and the ground doesn't seem to be, uh, "grounded". If I ground my multi meter to the firewall instead with the positive lead on the positive power wire for the motor and the fan switch on it reads 13.1v. If the fan switch is off it reads 0v. To test the motor I ran it off of my drill battery for a few seconds, which worked fine, until then it quit. Then I noticed my battery was 18v, not 12v. Oops. So now I have a fried motor *and* a bad ground wire. 😞 Job 1 is to remove the motor... easier said than done. The black assembly in the photo is indeed the blower motor assembly, however it seems that Monaco assembled all that and then built the dash around it, with no regard for how anyone would access it again in the future. With the top of the dash lifted away there was no way to either remove all of the screws holding the motor in, or all of the nuts holding the entire assembly on. There just wasn't room to access them all. So I ended up removing 3 out of 4 nuts holding the whole assembly to the silver metal box and then *melting* the plastic around the 4th screw mount to separate it from the assembly with a heated screwdriver to get the thing off, as that was the only tool I had that would fit. Now that it's off it's a simple matter to replace the motor + squirrel cage. I'm pretty confident 3 nuts will be enough to secure it back into place. I then dropped by my local NAPA store their replacement costs $132 Cdn! I knew that was high from folks here saying their's cost $20 and such, but took the one they had so I'd have it (we're leaving for a trip on Friday). Then when I got home I found one on Amazon (several, actually) for $48 Cdn, arrives on Tuesday. So I'll be returning the one I bought at Napa. I'm all for supporting local businesses, but that's a ridiculous discrepancy. I've thought about simply running an additional ground wire from the motor connector to the firewall, it's right there, but I'll probably end up removing the entire dash plastic tomorrow to see if I can trace the bad ground further. There is no connector near the motor and the bundle it joins seems to end up at the dash controls, so likely one of the large white connectors involved there, though if that were it, it seems strange that the Mode selector would work fine, but the speed control does not. Link to comment Share on other sites More sharing options...
Solution RoadTripper2084 Posted September 12 Author Solution Share Posted September 12 Okay, the job is done. What a frustrating experience that was, the only saving grace was that I could do it while snug inside the coach while the rail fell. So things I've learned: 1. On the root cause of my original fan failure... On 9/8/2024 at 11:32 AM, Benjamin said: Also check the ground from the connector. My ground is a flimsy clip on one of the mounting screws. Supply ground and hot, or check connector for hot and ground with fan "ON" "high". Bingo! The reason the fan stopped working in the first place was the ground wire through the connector was crispy. So I cut back the burned wire and directly connected the two ground wires with a solid crimped fitting. 2. The fan ground wire seems to have the resistor pack in its circuit, so connecting the fan directly to chassis ground makes it run full speed, continuously. Thus, the original ground wire must be used. 3. The replacement motor I purchased at Napa (Canada) for $132 Cdn turned out to be identical to the original fan that came with the rig (or at least the one that I took out, but it seemed original). Built in Canada, identical sticker, etc. on the outside. Only difference was the wheel plastic is black on the new one and white on the old one. So I decided to keep it / use it because it is a solid unit and to support my local manufacturers and retailer. 4. If I ever have to open my dash again I'd be very tempted to install a hinging system and some clips to secure the dash so it can be quickly / less destructively. Here's a picture of the hole where the fan assembly connects to the metal heat exchanger unit, and the plastic box on the other side of the firewall that houses the A/C coils. You can see where I left the bottom right nut on with the melted plastic around it. Not my finest work but got the job done. If my fan every falls off due to lack of securing nuts I'll be sure to let everyone know... 😉 2 Link to comment Share on other sites More sharing options...
Rikadoo Posted September 13 Share Posted September 13 Those connections are famous for overheating then failing the circuit. The slip fit between the two mating surfaces get loose with time then as i have found in high amp circuits fail an quit😡 1 Link to comment Share on other sites More sharing options...
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