Why does my Onan 4000 run for 3 seconds and quit after I replaced the carburetor and fuel pump?
If the board does not sense AC within about 3 seconds, it cuts ignition on purpose. Usual cause: glazed slip rings or worn brushes — not fuel.
Known technical issues
Field patterns the manuals miss
It starts then dies and I have oil in it. Could it still be the oil switch?
Yes. A stuck oil pressure switch looks like a fuel or board problem. Continuity to ground is a 5-minute check.
Code 32 or no secondary blink and the shop wants a whole new generator?
Code 32 is a frequent ghost when the module itself is sick. If harness inputs are good, replace the module — not a $2,000 unit.