MH wont start on chassis battery. Has 13V

doublev wrote:
I have a 2008 Country Coach Affinity. It will not start (not even try to crank) on the chassis battery. Everything lights up on the dash OK, it even shows 13V on the voltmeter. Turn the key and nothing.

If I hit the battery boost (which combines chassis with house battery) then I can start it fine.

I confirmed the batteries have 13V by disconnecting from shore power and putting voltmeter to the chassis battery. 13.05V. I checked the coach batteries (at this point they were running on the inverter) and they came in at 12.5V.

I think I can rule out the batteries... but I dont understand what is so special about battery boost-- why would the engine start on that if it is not the battery?

this is an automotive problem.

how long had the chaddis battery been isolated before you took the reading? you need to wait 5-10 mins before taking the reading.

also, check to see you have 12-volts at the solonoid switch and starter. sounds like a bad/loose connection and the boost is getting enough voltage to spin the starter. i'm betting on the starter connection.