The circuit breakers are thermal and eventually self-reset after tripping. I'm surprised your battery didn't become discharged overnight. It's hard to beat the combined experience of all the Volvo techs at a dealer for a problem like this. It might have taken you months to isolate the cause, even with the guesses you might have received from other Brickboard participants.
I don't think the lack of response indicated a lack of interest. More likely a lot of folks away on vacation and few good ideas among those who remained.