What model and year?  Onan has made a lot of changes over the yrs.

Why the parts swapping before you know what the problem is?  Typ ign is
powered by battery during start and when engine is running, self powered.

Hopefully Alan Robinson will see you post and respond.

Mickey

If your genset would run while you were holding the start button, then
neither the ignition coil, the condensor, or anything else you may have
changed were related to your problem. If you put everything back to the way
it was, the genset should run, and you -should- be back to your original
problem.

Since you haven't told us -which- Onan genset you have, the following is
generic information:

When the genset is starting, ignition voltage is supplied from the battery,
the controls ignore any stop signal from the local or remote
switches/wiring, and a signal from the oil pressure switch is not required.
For the genset to switch to 'run' mode, which allows it to continue running
when you release the switch, it must -not- have a stop signal, it -must-
have an oil pressure signal, and it -must- be generating.

Once you provide information on -which- genset you have, I'll be happy to
tell you what to check to determine what's causing the problem. Need to have
the full model and spec nr - should be something like 4.0BGE-1R/26104F or
4KYFA26100C or something similar.

Alan

Had this problem with a 6500 Onan several years ago.  After the Onan tech
spent three hours troubleshooting using an Onan service manual, he found a
loose wire where the wiring harness from the remote starter connected to the
side of the generator.  Corrected this problem and everything was back to
normal.  Moral of this story, check all electrical connections before doing
anything else.  You just might get lucky.

Don in Tracy, Calif.