Onan 4000 Generator 41

[lcwarnke]

I'm hoping to get some ideas from those familiar with the Onan Microquiet 4000 generator. I have a 2007 JayCo I've kept the generator maintained up until 2 years ago that put me in the hospital for about a year. So when I finally could get back to my RV, the batteries were dead, the fuel generator fuel pump was shot, so I replaced the fuel pump, fuel filter, sparkplug, air filter and new battery. The generator doesn't try to run, even with starter fluid. it immediately throws code 41.

I've taken the control board out. found a thread on testing J1-1 and J1-10 and seeing I get resistance ~22 ohms. I then put it back together and tested cranking over and found the voltage off of pin J1-1 to be 9.5 volts rather than 12. I'm now at about as much as I know to deal with the generator and electronics on it. I was blown away about how much new control boards run ~$600.

Before I throw in the towel I would love to get some other ideas.
Thanks.

[Old-Biscuit]

Troubleshooting........starts on pg 22 Section 6
*cranking sequence pg 25 and pg 37 (depending on which Spec)
http://www.rvwithtito.com/download/O...anceManual.pdf

Code 41 is control not sensing field or output voltage
Field Flash pg 29 and 41

[lcwarnke]

Thanks for the link and the pages. I'm so bummed about this code as there can be so many things. The generator sat for 1.5yrs without being started. And I really don't have the funds to take it to a onan mechanic and then have to pay big $$'s when I mostly hook to shore power, but I do want to fix it if I can fix it myself.

I did come across this article from "JustAnswers" I performed the tests. Everything checked out except on the J1 wire on my probe I'm measuring 9.5 volts rather than 12v. Does anyone know if this points to anything?



Code 41 is Rotor Fault.

There are a couple of conditions that can set this code.

I am not going to sugar-coat anything - this is going to be a fairly difficult one to troubleshoot, but it can be done with a bit of patience.

A good quality multimeter will be necessary for this.



Onan makes a special tool that plugs into the controller to make this diagnosis easier, but the tool is several hundred dollars. The average person can not justify the expense, so we will have to make do.



The first thing you need to do is to remove the controller.

The controller is the black box that the starter solenoid is mounted on top of.



Disconnect the battery cable at the battery.

Disconnect the battery cable from the starter solenoid, and pull it out through the oval hole in the side of the genset.

Disconnect the 8-pin plug located next to the solenoid, and pull the harness out the same hole.

Remove the 2 Torx screws holding the controller to the front of the base pan.

LIft the front of the controller mount up past the base, and tilt the controller to access the large plug in the bottom.

Disconnect this plug.

On the plug, locate the wires labeled J1-1 and J1-10.

Set your meter to ohms, and connect one lead to each pin in the plug that corresponds to these 2 wires. You should get a reading of about 22 ohms.

Now remove one lead, and place it to a good ground. It should read no continuity.

If not, we have to suspect a bad brush or rotor winding, and we will have to completely disassemble the set to check them out.



If these 2 checks are good, reconnect the plug to the controller.

Set your meter to DCV, and connect the black lead to a good ground.

Reconnect the battery cable to the starter solenoid.

Back probe the red lead into wire J1-1.

Press and hold 'START' for 3-5 seconds.

It should read about 12V.

[lcwarnke]

Turns out it was the fuel solenoid causing the error code 41. The fuel solenoid was gummed up and no longer able to retract allowing fuel to flow. I removed the fuel solenoid at the bottom of the carburetor, cleaned it out by taking it apart, put it back together and the generator purrs like a kitten.

I thought the issue was some terrible electrical issue or mechanical, but just a sticky fuel solenoid.