House battery charging by alternator
I am trying to understand how the charging system works on our 2007 Coachmen Concord. It seems that the truck alternator charges the house batteries at different times. For instance on a recent day t...
Forum Discussion
CA Traveler wrote:
Most likely problem is the solenoid as significant amps are involved and DC is prone to pitting the contacts.
Yes, battery isolator solenoid failures are VERY common.
Easiest way to troubleshoot them is to temporarily connect a 12 volt test light or voltmeter across the "coil" terminals on the solenoid to confirm that the coil is energized, and measure the DC voltage across the two high-current terminals on the solenoid (while the engine is running).
If you measure any significant voltage across the high-current terminals (i.e., more than a few dozen millivolts), the contacts inside the solenoid are no longer conducting current like they should - and the solenoid should be replaced.
