Ask PYS: Power

Charging Issues, ACR Fuse Troubleshoot – Thomas, on Sep 25, 2015 asked:

The charging of both banks of our batteries has been going well over the past couple of months since you did the work on the system. We are out for a few days and odd things are starting to happen. When on shore power, the house battery charges and the start battery does not. When under way, the house battery does not charge and the start battery charges. If you have any short term thoughts that I could check I would appreciate it.

Looks like a fuse on the ACR circuit blew. To be specific, circuit between both house and engine is via Automatic Combiner Relay (ACR). There is a fuse located at each battery. One of them probably blew.

If you follow the wires from this ACR to both house and engine, this will lead you to the fuse on each side of circuit.

We’ll come and have a look ASAP. But in the meantime, if you feel so inclined, try tracing the wiring and seeing if my hunch is right.