DrewE wrote:
Do you know for a fact that the chassis battery is good? That is, have you had it load tested? It may well need replacement, particularly after being discharged rather deeply a few times (and who knows how many more before you acquired the RV).
The voltmeter when the engine is running tells you next to nothing about the battery status since the alternator is supplying power. All you can tell is that the alternator's voltage regulator is more or less working properly.
The other thing to ascertain is what loads are on the chassis battery when the engine is off. It does sound like some things are wired in a non-intuitive way. The radio, in particular, may actually be powered from the house battery rather than the chassis battery, or perhaps has a switch to select between the two batteries; various RV makers do that in different ways. (This is true even when the radio is mounted in the dash.)
In general, when it comes to details of the electrical systems, there are some things that are rather common, and some that are less so, and some that are downright wrong, but few details that are absolutely "standard."
Thanks for the reply, Drew!
No, I don't know that the battery is good, haven't had it tested. I looked to see if there were any date on it but I didn't find one. I am sure that the Sirius wasn't original---the owners left a receipt in with the manuals showing they had it installed a few years ago.
Hmm, what if they did wire the radio or other things to the coach batts instead? Interesting.
