Battery Boost not working

Moffittclan wrote:

Dale.Traveling wrote:
Easy to check the AUX Start/Boost circuit. Two ways to do but which works depends on how you coach is wired.

Turn on a convent 12VDC light. Trip the house battery disconnect. Light should go out. Hit the AUX Start/Boost switch and light will come back on.

-or-

Turn on a convent 12VDC light. Disconnect the ground terminal from the house battery bank. Light should go out. Hit the AUX Start/Boost switch and light will come back on.

The AUX Start/Boost circuit works both directions not just to send extra power to start the engine but will also feed power back to the house.

Perfect! I know what I'm doing tonight while I'm installing the new chassis batteries! Thanks for the help!

Forgot one additional step. Either shut off your AC to DC convertor/charger or unplug shore power. If the converter is on the light will never go out or it might. Again depends on how your coach is wired.

You can take the test one step further. With the convenient DC light out start the engine. If the light comes back on after a short time period then the engine alternator is feeding the house DC circuit via the AUX Start/Boost circuit and will help keep a charge on the house batteries when going down the road. This may also confirm that the convertor will also keep the chassis batteries charged when plugged in to shore power. If the test works you could use the generator to recharge the chassis batteries but it will take time depending on how depleted they are. At 9VDC that could be all day if they even recover at all. The whole process is a little more complicated with voltage levels, priority charging and such.

But, and it's a big one, it all depends on how your coach is wired. Add in an every deeper darker problem of former owner undocumented alterations (used to call the Sailor-Alts during my Navy days) and there's no telling how you system might behave.