Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > TRAVEL TRAILER, 5th WHEEL & TRUCK CAMPER FORUMS > Toy Haulers Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 01-16-2022, 05:02 PM   #1
Junior Member
lcwarnke's Avatar
Join Date: Apr 2013
Posts: 7
Onan 4000 Generator 41

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.
lcwarnke is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free! RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 01-17-2022, 09:09 AM   #2
Senior Member
Old-Biscuit's Avatar
Join Date: Nov 2015
Posts: 24,654
Troubleshooting........starts on pg 22 Section 6
*cranking sequence pg 25 and pg 37 (depending on which Spec)

Code 41 is control not sensing field or output voltage
Field Flash pg 29 and 41
I took my Medication today. HAVE YOU?
Dodge 3500 w/Tractor Motor & NUWA 5vr
US NAVY---USS Decatur DDG-31
Old-Biscuit is offline   Reply With Quote
Old 01-23-2022, 01:09 PM   #3
Junior Member
lcwarnke's Avatar
Join Date: Apr 2013
Posts: 7

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 is offline   Reply With Quote
Old 01-31-2022, 10:29 PM   #4
Junior Member
lcwarnke's Avatar
Join Date: Apr 2013
Posts: 7
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.
lcwarnke is offline   Reply With Quote

generator, onan

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Onan MicroQuiet 4000 generator questions JC Andrews RV Systems & Appliances 10 06-17-2013 06:56 PM
onan generator, 4000 whitail Class C Motorhome Discussions 28 05-31-2012 07:23 PM
Where is oil Drain for Onan 4000 generator bassoneman Class C Motorhome Discussions 6 04-10-2012 07:38 AM
Onan 4000 generator question duncanracing Fleetwood Owner's Forum 4 07-24-2011 07:30 PM
Found it-- now what? 4000 Onan generator Izzyblueye MH-General Discussions & Problems 1 03-18-2010 11:44 AM

» Featured Campgrounds

Reviews provided by

All times are GMT -6. The time now is 04:49 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.