SJ-Chris wrote:
Most RVs are designed to have the alternator charge the house batteries through a solenoid while the engine is on (...presumably while driving from one campsite to the next). A built in feature of that solenoid is an "emergency start" switch usually mounted on the dash or near the driver side steering column. When working properly, if you push and hold that button you should hear a "click" and the solenoid temporarily connects the house batteries to your chassis battery so that you can use the house batteries to help jump start a dead/weak chassis battery. This is all by design.
It is not rare at all for that solenoid to wear out and break. They are cheap and usually fairly easy to replace. Let us know how it goes.
-Chris
What Chris said, above. Sounds, from your previous posts, that your old RV may have already have that feature. ... boost at least. you could simply change that momentary contact boost switch on the dash to a toggle switch that will stay on when you want it ... thus maintaining your starter battery connected through that solenoid you found to your house batterys. You should check that that solenoid still works ... they can and do fail at times ... but easy to replace.
