Problem Starting Generator

[steve zannella]

This morning, coach in storage, I tried to start my generator and no crank so I started my engine then tried generator it started right up.
Next day checked my batteries coach and chassis both at 12.6 volts. Generator still would not crank unless engine running.
Any ideas.

Onan 12.5 2004 marquis

Thanks Steve

[gregott]

May sound dumb, but any chance you have the battery cut off switch on?

[Gerald Farris]

Steve,
What is the voltage across the two 12 volt cables at the generator when you try to start the generator? It sounds like you have a corroded or poor battery cable connection somewhere.

Gerald

[Joel Ashley]

Sounds like some resistance somewhere;  for starters, check your battery post connections for corrosion and tightness, as well as the main chassis ground and genset main ground points, and the leads at the generator’s solenoid.

Joel

[Lee Welbanks]

Steve,
I had the same issue with my 06 PT  the gen would not start unless the Cat was running. I put a volt meter across the battery cables at the gen, 13 volts hit the start on the gen and it dropped to around 7 volts. Problem was the cable from the front run box to the generator was too small wrong gauge and was routed much to long. Went to the local welding store and bought 12' of single O welding cable and copper ends. Replaced the cable and also the ground cable which also was too small, now it starts no problem.  Don't know if that is your problem but they seem to undersize cabling most of the time.