I have an 88 Sunrader with what appears to be a solenoid-based isolator setup (little cylinder that looks like the old Ford starter solenoids, four wire).
My problem is that when it sits for weeks not being used, plugged into shore power, the chassis battery will be dead and I will have to jump start the vehicle. When I check voltages, running the engine charges both chassis and house batteries, but shore power charges only the house battery.
Is this how it is supposed to work? If so, is there a workaround so that shore power also charges truck battery while still maintaining isolation when disconnected?
If this is not how it is supposed to work, any suggestions on troubleshooting?
I should add that about two years ago I was having a problem with the chassis battery discharging overnight. I took it to an auto electric shop, which told me that my radio was discharging the battery, disconnected it, and told me that I needed a new isolator (identical in appearance to the solenoid-like one that I had had before.) The one that they sold me looked just like the old one and I hooked it up. I have since reconnected the radio and do not have the problem with the chassis battery discharging overnight, so I think that they were full of it on that, just finding the minimal current that keeps memory going in the radio. Long story short, I am pretty confident that the isolator, being pretty new, is not faulty, not to say that it is hooked up right.