Thor Chateau 2020 not charging coach battery from alternator
This is actually my neighbor's RV. Coach lights and accessories work. Shore power and generator charge the battery. Alternator does not. Found the isolation contactor under the hood below the coolant tank on the drivers side. 2 large red wires, one to the main battery and one disappears below the rig, I assume to the coach batteries. Measure the voltage from each terminal to ground, 12v (ish) on one, zero on the other terminal. Start the engine, contractor goes click and now we see 13v (ish) on both terminals. Is there something (fuse, breaker) between that contractor and the coach batteries? If so, where? I looked all over and couldn't find it. I have another friend with a Jayco and has the same problem.