Community Forums

Waggy · 06-07-2014, 11:50 AM

My brother and I have been having a suggestion on how the aux (coach)battery gets charged by the alternator and was hoping for some help. When I put the volt meter on the main battery and the engine is going I get 13.54 volts or so. When I put it on the other Aux battery I get 12.50 which is no change! It has two switches in the unit to disconnect the Main and the Aux battery and we have put them in all possible combinations. There are two units that look like solenoids in the electrical box under the "hood" and another type by itself on the left side. When we start the engine, I hear no solenoids connecting as I had expected.
I can find the manual for the unit but not the electrical diagrams. We are about to get a new battery, and I would like to check that it is charging before going out camping. Without power these units are useless!
Any help would be appreciated.

eddieelk · 06-07-2014, 12:17 PM

On my '87 Pace w/454 chevy, the solenoids would only click when you turn the main/aux switches on or off. Since the motor starts, the main solenoid is on. With both switches on, check the voltage going into and out of the solenoids. If there is power coming out of them, then it might be the ground on your aux batteries. If there is no power coming out of one of the solenoids, up a jumper across the two large posts on either side, and check your output. Eddie Elk.

BFlinn181 · 06-07-2014, 01:17 PM

Many RVs have a solenoid that only connects the house and chassis batteries when it senses charging voltage to prevent drawing from both sets of batteries when starting or drawing from the chassis battery when using house 12 v. Have you checked if both sets of batteries are being charged when on shore power? The solenoid I'm talking about should kick in when charging from that source also. Check same way you discovered no charge on alternator. There is often a delay built in to allow chassis batteries to charge first before house batteries get charged.

Old Bounder · 06-07-2014, 01:31 PM

Here is the documentation that you need to trouble shoot your charging problem. Let me know if you need any help in understanding the system or process.