Fired up the Onan generator the other day to exercise both it and the roof A/Cs.
The first sign of trouble was the generator acted like the chassis battery was low. Took several tries on the switch before it finally spun over and started. It ran fine but I wasn't getting any voltage in the coach. Did some searching online and found a troubleshooting guide. Did a couple of quick checks at the fuses and connections at the generator but those things looked fine. Pulled the coach breaker panel out to find the transfer switch but it appears to be a sealed unit. Smacked it a couple times but no joy.
The one thing that I should have focused on more was each time I tried to start the genny it took several tries to get it to catch and spin over. Acted like a low battery but the battery had good voltage and the chassis engine started right up without any hesitation.
Finally, I opened the battery compartment and started checking connections there. Found a slightly loose connection where 3 main cables connect to a solenoid relay. Tightened it up and now it all works fine. Genny starts up first try and transfer switch clicks over with full voltage. So often it is the basic things that can go wrong and its so easy to look past them to more complex systems.