Genset Runs but no 120v to Coach

[rpasetto]

Started up the genset, Onan 4000, as usual. No 120v to refer, microwave or outlets in coach. I looked over the Winnebago diagram (screen-shot below) which show a junction box (red Arrow) to rear of genset with a connection from genset cable to one running to the the Transfer switch (green arrow) at rear. I checked the wiring in the Junction box with a VOM and got zero volts.

I can think of two possibilities: either the circuit breaker in genset has gone bad or there's something wrong with genset's control board. Not sure how I can check whether problem is with one or the other of these.... or something else.

Before I start pulling things apart... Suggestions? Comments?

[tim myers]

Have you checked the generator mounted circuit breaker, just cycle it off and on see if that helps.

[Morich]

Good thought by Tim as the breakers can look good but need to be pushed fully off and then fully on at times.
You may need to chase a drawing for the specific model genset?

[ZimBob]

In addition to other posters' suggestions, I had a similar experience and wound up replacing the automatic transfer switch. If it helps, I posted about it here.

Best of luck!

[rpasetto]

Originally Posted by tim myers

Have you checked the generator mounted circuit breaker, just cycle it off and on see if that helps.

Maybe I wasn't clear when I asked if the the circuit breaker in genset has gone bad, I'd already tried resetting it a few times. There doesn't seem to be a way to test at the circuit breaker terminals without some disassembly, including taking the start switch out as well since the circuit breaker is mounted under it.

[rpasetto]

Originally Posted by ZimBob

In addition to other posters' suggestions, I had a similar experience and wound up replacing the automatic transfer switch. If it helps, I posted about it here.

Best of luck!

From the Winnebago diagram above it appears the genset output goes to a junction box (red arrow) and then to a cable toward the rear that goes to the automatic transfer switch (blue arrow).

I get zero volts at the junction box.

[rpasetto]

Looked online, there's a youtube video (see below) which shows taking out the circuit breaker but the video starts where the start switch and mounting panel has already been taken already off. I could guess at the sequence there, but then I'm not sure if I could hook up the genset start switch to test the breaker while running.

https://youtu.be/6GZN__Y1A9s

[tim myers]

Originally Posted by rpasetto

Maybe I wasn't clear when I asked if the the circuit breaker in genset has gone bad, I'd already tried resetting it a few times. There doesn't seem to be a way to test at the circuit breaker terminals without some disassembly, including taking the start switch out as well since the circuit breaker is mounted under it.

No sir you were clear, I just missed your reference to the genset mounted breaker

[Morich]

At one point, several months or a year back, we had a really indepth discussion of fixing the board on a genset.
That posting involved the start switch at the inside locations not working but the switch on the genset did work! He chose to start the search at a front switch and we chased the lead all the way back past the monitor panel, etc until getting to the genset and he finally took the board off to find an open solder trace on the board.
A person with far more dedication that I can manage on most cases any more!
But that was too far back to remember or find in the listings. What I DO remember was that he had a good set of electrical drawings that showed wire by wire what the board did.
Somewhere there is access to that info but finding it may be a challenge. Some places put lots of info out, others none!