Thor Forums - View Single Post - HELP

Judge · 05-11-2020, 10:59 AM

Couple questions...

- What model 28A (Chateau, Four Winds)?

- What year?

- Are you plugged into shore power when it is sitting?

- Is the Use / Store switch in the "Use" or "Store" position when it is sitting?

- Who said the chassis (starting) battery was fine and brand new (dealer, roadside assistance)? Did they check the Specific Gravity of each cell?

There are a wide number of possibilities so we need more information to help. The chassis (starting) battery is independent of the house batteries.

I assume you made sure a map light or something else was not left on in the cab and that is not draining the chassis battery.

Here are a couple pointers....

1) The emergency start switch ties the house batteries and chassis battery together to give the chassis a boost to start the engine if it gets discharged for some reason.

If the chassis battery is completely dead, you would need to press and hold the Emergency Start switch for a bit to allow the chassis battery to get some current moving through it before trying to start the engine.

There is a solenoid under the hood that engages when you press the Emergency Start switch. If you don't here it click when you press the switch, check the fuse for it (which should be attached to the solenoid itself.

2) If you are not plugged into shore power when it is sitting and you have the Use / Store switch in the "Use" position, the house batteries can discharge over time. Also, if you have an Inverter it will be wired directly to the house batteries. If the Inverter is left on, it will also drain the discharge the house batteries.

In any case.... the house batteries are independent from the chassis batteries so even if they get discharged, it should not discharge the chassis battery.

3) On most Class C's, the chassis battery will not charge when plugged into shore power. You would need to install a Trik-L-Start so the coach charger can maintain the chassis battery or you would need to keep a battery maintainer on the chassis battery if it sits for long periods of time.