2006 3400 with a 12V problem

[Syndi]

I'm stumped. This may not be saying much, but... I am having problems with my 12 volt system on my 2006 3400. Started when I was putting my front legs down. Motor quit with the problem found to be the 30amp inline fuse. Replaced it with a 30 amp circuit breaker and thought the problem was fixed. Next morning I had problems with the CO2 detector, my frig went off, the fan with motor in top of unit would not come on and no lights that are 12 volt powered. The 50 amp breakers on the wall behind the battery, one was bad and the other good. Straight wired it until I could get another 50 amp breaker to replace and all was well again for 12+ hours, then all quit again. Have traced down as many wires as I can find without finding the problem. My son (my electrician) is 2000+ miles away and trying to diagnosis and fix with me being his eyes and hands and he deserves a lot for this. Still no answer. Is there a way to make the frig come on and operate by gas while we are finding out what this problem is?