Community Forums

perryg362 · 05-04-2022, 05:30 AM

i recently purchased a 2000 holiday rambler ambassador with the upgraded cummins. it seems i need to run the engine for a few minutes before the 12 volt system kicks in. after that i can shut the engine off and the system will stay on. is this normal? i've owned other rv's and never ran into this. looked through the manual but that was no help

MrMark52 · 05-04-2022, 05:40 AM

Assuming it’s your house 12 volt power that is the problem and your chassis batteries are good - how are your house batteries?

Many coaches have a device that charges the house batteries from the engine generator. But it will not switch over until the chassis batteries are fully charged. It will then charge the house batteries until the chassis batteries drop below a certain charge threshold or you kill he engine.

twinboat · 05-04-2022, 05:46 AM

Check the house battery cable connections at the batteries and chassis connections.

At the batteries, you need to remove and clean them, even if they look fine.

Dirty connections block power flow, but many times a charging current can burn thru the corrosion .
When you run the engine it sends a charge to the house batteries from the chassis batteries.

YC1 · 05-04-2022, 05:54 AM

Ditto Twin Boat and be sure to take pictures before doing anything. I mean lots of pictures. Too many reports of odd behaviors after doing things like this caused by one wire being dropped behind something.

As suggested it sounds like your battery combining system is kicking in and you may be running on your engine/chassis battery versus the house batteries.

Are you connected to shoreline during this test/

perryg362 · 05-04-2022, 07:40 AM

maybe so. if i leave the key in the "ON" position without turning anything off or on the 12 volt system will run for about 5 minutes, then it shuts down kind of like newer cars with entry/exit lighting on a timer

wolfe10 · 05-04-2022, 07:44 AM

Quote:

Originally Posted by perryg362

maybe so. if i leave the key in the "ON" position without turning anything off or on the 12 volt system will run for about 5 minutes, then it shuts down kind of like newer cars with entry/exit lighting on a timer

Please tell us EXACTLY what 12 VDC items work this way. Basically, are they house systems (like overhead lights) or those items that only work with the ignition on (like dash HVAC fan)?

From your digital voltmeter, what is voltage at chassis battery bank? At house battery bank?