The scenario; Generator will start but will not run. I traced it down to plenty of current to start side of fuel solenoid but no current to run coil in solenoid. Ran out of knowledge and got the kid across the street for help. ( he's only 40 ). He is the lead electrician at a plant in Oakdale that builds fire engines. We check the relays, we check everything. No luck. Then he says, "the sensors operate on when they are triggered they break the ground, and therefore the circuit and generator stops running." We pull all the connections clean them good and hook everything back up. Test fire.....SUCCESS. Just like it came off the floor in Nagadoches. I was all set to order a new control board tomorrow, and install it. Maybe a coach buck saved.
Total cost of the fix 4 shots of my best Tequila ( 2 each ) and a couple of beers to wash them down.
Moral of the story here is as others on this forum have said, your ground system is CRITICAL to the health of your electrical system. Corrosion is an insidious unseen beast that can get you. You Newbies with older coaches like mine take heed. If you get an electrical gremlin make sure the ground is good!
Hush your going to destroy a multi million dollar parts swapping industry. Motors and other stuff moves and twists sometimes breaking the ground path. Hey as one service manager told me "we don't make no money on labor"
We can all find Fault with our coach but most of the time it's the lack of a good ground.
With 12V systems I always begin with "It's always the battery." Once that out of the way "It's always the ground." Now my partner is a degreed electronics engineer, with an intuitive grasp of the goings and comings of electrons. Me.? I know enough about electronics to be dangerous, but give me a tool room's machine tools to work with, step aside and watch.
So as a learning moment, Lynn made me repair out generator myself.
Here's the write up. I Repaired Our Onan Generator's Electronics! | arts-attic.com (http://arts-attic.com/blog/?p=1825)