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.