No 12 V juice--battery or converter?

[coolmom42]

My new-to-me 2014 Coachmen C (21QB) has no 12 V juice without the generator running. As in, the lights won't even come on. The battery is a cheapo, previous treatment unknown. When I looked at it prior to buying, the generator was running, because it was a really hot day & I wanted to make sure the AC was working.

It's possible a light was left on inside the first day I got it home, too. That may have flat-lined the battery in a couple of days.


If the 12 V systems work when the generator is running, does that mean the converter is working?

If the 12 V systems work when plugged in to 110 V, does that mean the converter is working?


The generator hour display has a tiny battery icon and as best as I can see it shows a symbol of a battery charging (zigzag in the icon.) Does that mean that the generator is charging the battery?

What battery does the generator use to crank up? It starts just fine.

[enblethen]

does sound like converter is working.
There is commonly a circuit breaker or fuse adjacent to the battery(ies). It could be bad.
The battery disconnect could be in the off position. Cycle it. You should hear a click out of it. That means the control circuit is good. No click would indicate a bad control circuit power or a bad relay.

[wa8yxm]

Dead Battery
Tripped circuit breaker or blown fuse. this breaker or fuse should be near the battery and likely is not part of the main fuse panel

Bad connection battery or ground end of negative cable

Disconnect switch in the disconnected position.
Defective disconnect solenoid.

[midnightsadie]

find some body close to you that has a rv get them to walk you threw things. better than throwing money at it. then finding out it was a simple fix.

[cavie]

1ST. Remove the battery and have it load tested at any auto parts store. 2nd disconnect the output wires of the converter and check the voltage of the 12 volt output terminals.Converter should operate with shore power or generator. It is on it's own 15 amp breaker.

[MrWizard]

Sounds like the converter is working
Try this test
With the generator on and you have 12v power
Flip the the battery disconnect switch several times
The latching relay might be stuck
Or if the batteries are discharged the latching disconnect relay might not have enough power to engage
Check to see if the batteries are getting charge voltage

Somebody will post where the relays are located
And any fuses

Generator can be wired chassis or house
The Onan in my RV is wired to the engine battery