7500 Onan Generator won't Start

[Bill R]

Jim - my manual says that if I get fault code 3-6 to hold down the stop button for 30 seconds to prime the generator.  Did you have her do that?

[Tom Cherry]

23 minutes ago, Bill R said:

Jim - my manual says that if I get fault code 3-6 to hold down the stop button for 30 seconds to prime the generator.  Did you have her do that?

Fascinating.  AS USUAL...all my switches WORK the same.

What Bill says is true.  If you take in a Genny and say..  This sucker takes a while or won't start...the Tech will then HOLD DOWN (like you were turning it OFF, the Start button and prime it.  I've seen them PRIME it a few times.  Then hit the START and it Cranks UP.  The comment....as they get older, they need to be primed more.

Mine is a little finicky that way.

NOW that Jim has provided the "TURNS OVER", then that eliminates the starter.  Don't KNOW why the Clicking and not starting from the Genny Switch.

BUT...IF it has NOT BEEN PRIMED...I'd PRIME it.  Prime it AGAIN...and maybe a third time...and then try.

The instructions in the manual, by my interpretation, is "This sucker won't start....Well then PRIME IT and see".

But, that's how I read it and my experience...

I guess we will see...

He'll keep us informed.  IF SHE changes the Fuel Filter... it will DEFINITELY need to be Primed....probably several times

 

[jacwjames]

35 minutes ago, Bill R said:

Jim - my manual says that if I get fault code 3-6 to hold down the stop button for 30 seconds to prime the generator.  Did you have her do that?

Yup, mulitple times

Well, she got the fuel filter changed, still no joy.

So the plan now is to travel to the Loves truck shop in Normal on Monday.  Get up first thing and go to the Cummins shop first thing on Tuesday

I told her to play the "Poor Pitiful Me" game, go with a couple of the small dogs and the crippled older Curly Coated Retriever and  with a tear in her eye and beg for help. 

Told her to leave the 150lb Anatolian Shepard in the coach with the the back up plan to take him in and leave him until they fix the gen set. 

Hate the feeling of helplessness but it is what it is. 

Edited May 25 by jacwjames

[Ivan K]

Cracking an injector line to see that fuel actually makes it there would be my next step but she is a trooper for doing the filter already.

[jacwjames]

11 minutes ago, Ivan K said:

Cracking an injector line to see that fuel actually makes it there would be my next step but she is a trooper for doing the filter already.

Ya, I was surprised with what she was able to do.

Jjust getting the injectors is a chore so we won't even go there.  Hoping the Cummins shop can fit her in.  

I'll do some checking on a backup plan, her next destination is Dundee MI

[96 EVO]

42 minutes ago, Ivan K said:

Cracking an injector line to see that fuel actually makes it there would be my next step but she is a trooper for doing the filter already.

If I managed to convince my wife she needed to get diesel all over herself changing a fuel filter, and it still didn't run, I'd be a 'Dead Man Walking' 😮!!

[Ivan K]

6 minutes ago, 96 EVO said:

If I managed to convince my wife she needed to get diesel all over herself changing a fuel filter, and it still didn't run, I'd be a 'Dead Man Walking' 😮!!

And I would be joining you in short order!

But seriously, cracking the Injector line through the side opening is child's play compared to what she has already done. At least on ours.  Also surprised  that no one around her has stepped up to help her.

 

Edited May 26 by Ivan K

[96 EVO]

Does the 8.0 have the same rectangular fuel filter as the 10 and 12.5K?

Those filters take a lot of priming to get them filled.

[jacwjames]

I don't have a side opening (memory), maybe a small cover on top

Tomorrow I'll have her try priming some more.  I ran out of fuel one time and it did take a lot of priming to get it to finally start. 

1 hour ago, 96 EVO said:

If I managed to convince my wife she needed to get diesel all over herself changing a fuel filter, and it still didn't run, I'd be a 'Dead Man Walking' 😮!!

Only explanation I have on her trying to get it going is "For The Dogs", they need the generator when it gets hot. 

[96 EVO]

27 minutes ago, jacwjames said:

 

Only explanation I have on her trying to get it going is "For The Dogs", they need the generator when it gets hot. 

I hear ya!

We recently paid a ridiculous power cost to make sure our pup was at a comfortable temperature while we went out for dinner.

[jacwjames]

4 minutes ago, 96 EVO said:

I hear ya!

We recently paid a ridiculous power cost to make sure our pup was at a comfortable temperature while we went out for dinner.

Yup but she's traveling  with 11 dogs, they are just like little box heaters putting off lots of heat with every pant.  

[Happycarz]

Jim, have her take a look at the multi pin connector along the passenger side of the generator. Those are a weak link in the system and cause different issues. One friend had one of the pins loose in that multi pin connector. A few have had bad contacts between the male and female connector. A good place to look since both switches don’t have the same results when pushing.

 

[Happycarz]

Clean it several times with electrical contact cleaner, disconnecting and reconnecting it several times. Tug on all the wires while at it, to be sure each is secure in its socket.  

[jacwjames]

10 hours ago, Happycarz said:

Jim, have her take a look at the multi pin connector along the passenger side of the generator. Those are a weak link in the system and cause different issues. One friend had one of the pins loose in that multi pin connector. A few have had bad contacts between the male and female connector. A good place to look since both switches don’t have the same results when pushing.

 

It gets complicated.  I installed a EC30W remote start system to the generator.  To do this they supply a "Y" splitter that connects to the original wiring harness and the goes to the remote and house wiring harness.  Everything zip tied to side of generator. 

I'm aware of issues with the connector.  The coach has been parked in the garage since last Oct and only drive from E TN to ILL Tuesday -Wednesday. 

Not saying it might not be an issue but seems unlikely.   I'm going to try and talk her through it. 

[Tom Cherry]

3 minutes ago, jacwjames said:

It gets complicated.  I installed a EC30W remote start system to the generator.  To do this they supply a "Y" splitter that connects to the original wiring harness and the goes to the remote and house wiring harness.  Everything zip tied to side of generator. 

I'm aware of issues with the connector.  The coach has been parked in the garage since last Oct and only drive from E TN to ILL Tuesday -Wednesday. 

Not saying it might not be an issue but seems unlikely.   I'm going to try and talk her through it. 

Complicated is an understatement. OK…you’ve explained, to my satisfaction, “what MAY have caused” the discrepancy in why the switches start differently.  Still eludes me.  BUT, when one hears clicking….power to the starter solenoid.  When one has the engine turning over….should be sufficient cranking power.  When one gets the fuel 3-6….and a new filter is in….and been adequately primed….then there, can be, in MY limited experience….only two issues.

First, there is a pinhole leak in the fuel line from the tank.  That has plagued many, many times.  OR…

There is a board problem and only a tech can dig in.

I hope others can chime in.  My hat’s off to your wife.  We need to have her start posting.  I totally realize the gravity of the situation….and wish I could offer more…

Keep us posted.

[Dr4Film]

Jim, are you retrieving the fault codes correctly per the manual?

You state that the first set of blinks is 3. Are you stating that you are getting a 3 first then a 3-6 second?

Then you should have TWO more sets of Blinks which are the second level fault codes. Read the paragraph in bold below.

So, you should have two numbers following the 3, such as either a 1,2,3 or 4 followed by either 1,2,3,4,5,6,7,8 or 9.

Here is a Copy & Paste from the manual for the 7.5K generator.

First-Level Fault Codes: The genset controller
provides extensive diagnostics by causing the status
indicator light on the Control Switch to blink in a
coded fashion. Following a fault shutdown, the indicator
light will repeatedly blink 1, 2 or 3 blinks at a
time.
• One blink indicates shut down due to high temperature
• Two blinks indicates shutdown due to a loss of
engine oil pressure
• Three blinks indicates shutdown due to some
other abnormal condition.

Second-Level Fault Codes: For a 1-blink or 3-blink
first-level fault code, one touch to Stop brings up a
second-level fault code. This code consists of 1, 2, 3
or 4 blinks, a brief pause, and then 1 to 9 blinks.

The first set of blinks represents the tens digit and the
second set of blinks the units digit of the fault code
number. For example, Fault Code No. 23 would appear
as:
blink-blink—pause—blink-blink-blink—...
NOTE: Fault Code Nos. 1, 2 and 3 are first-level faults.
Avoid interpreting them as second-level Fault Codes
11, 22 and 33. The pauses between repetitions of the
fault code are longer than the pauses between the
tens and units digits of the the code. For example,
Fault Code 33 would appear as:
blink-blink-blink—pause—blink-blink-blink
—longer pause—
blink-blink-blink—pause—blink-blink-blink—...
Restoring Fault Code Blinking: The fault code
stops blinking after five minutes. Press Stop three
times within five seconds to restore blinking. Note
that the last fault logged will blink, even after the
condition that caused the shutdown has been corrected

Edited May 26 by Dr4Film

[Just Jim]

I have nothing to add except, Jim you have got a trooper of a wife!  Number 1, mine would never go anywhere in the coach by herself and 2nd... certainly would not do any mechanic work.  Definitely a keeper. 

[Dr4Film]

If the blink code is really 3, 3-6 then this is the troubleshooting steps for that specific blink code.

ENGINE STOPPED FAULT—CODE NO. 36
(Engine stopped without command by controller)
Corrective Action:
1. Check fuel level. (Note: The genset fuel pickup is probably higher than the vehicle engine pickup.)
2. Prime the engine fuel system by holding the control switch down in its Stop position for at least 1 minute.
3. Check the engine air filter and remove any blockage (Page 16).
4. Check for mechanical damage.

[Dr4Film]

As an example - back in 2017 my 7.5K generator in the Windsor  would only run for 4 minutes and 55 seconds. The fault codes were 3 / 2-4

Failed Coolant Sensor. Had Cummins replace and has been perfect ever since for the new owner.

[jimc99999]

16 hours ago, jacwjames said:

I don't have a side opening (memory), maybe a small cover on top.

The side cover is next to the control panel. 

 

If you ever get a code 19 the problem is probably that white wire in the upper right of this picture. As you can see it’s broken here, and of course it waited to break until we were crossing the country in a heat wave. 

The side cover isn’t difficult to remove but it is annoying to re-install. 

[Dr4Film]

That side cover is how you get to the fuel filter to replace it. At least that's how the shop did it when I was watching them service the generator.

Edited May 26 by Dr4Film

[jimc99999]

8 minutes ago, Dr4Film said:

That side cover is how you get to the fuel filter to replace it. At least that's how the shop did it when I was watching them service the generator.

My generator is not on a slide and has a trap door underneath the fuel and oil filters. I removed that cover to replace filters once but with the annoyance factor of reinstalling the cover I think it’s just as easy through the bottom trap door. 

[jacwjames]

I believe she checked the codes right, she face timed me while doing it and we did ultimately get a 3  then   6 blink code.

She just filled with fuel, pumped 75 gallons so still had ~53 gallons in the tank.  I know when I ran out of fuel it took 100 gallons so she was far from empty.  She shut the generator off, hit the road, and when she arrived at her next destination it wouldn't start.  It didn't run out of fuel.

She changed the fuel filter from underneath, yes the side panel can be removed, ~15 10mm screws across top, back and sides. 

Going to have her try pulling codes again. 

Then priming more several more times and trying to start. 

 

Good or bad my wife has learned to become pretty independent, the last 3 years I worked I was either living in another state and/or traveling so she had to be pretty self sufficient.  The last year I worked I was gone 250 days, either in Canada, Spain, or Bolivia, but that's a whole other story🙂

[jacwjames]

OK, she tried to recover the codes again and got the same results,  3-6 code

Question>>> how do you check for and recover a second set of code

 

She tried to start, I had her prime it a couple time and then try to start using the button on the generator.  It worked as it should you can hear it priming and then can hear the starter kicking in and then engine turning over at a good speed so I don't think it's a battery connection.   But it didn't start, didn't even sputter or try to start. 

I couldn't hear the fuel pump taking pressure so can't tell if it is priming, the pump is working but not sure if it is pumping fuel.

[jimc99999]

How long is she priming it for? If the genny runs out of fuel or I replace a fuel filter, I have to prime it for at least a minute. If it still doesn't start, I prime it another 30 seconds between attempts to start. It's been a bit so I don't remember how many attempts this typically takes but it takes a lot of priming sometimes. I assume if you hear the clicking while holding the stop button, the fuel pump must be running.

If she's already replaced the fuel filter, next step I assume would be to check if that filter now has fuel in it, if not then the fuel pump must not be working properly. 

I'm pretty sure when the governor wire is broken the starter won't crank the motor so it's probably not that.

Edited May 26 by jimc99999