Volvo Tri-Pac

Did you check the main fuse holder by your battery?

 

In the back of the tri-pac box behind the motor and above the alternator there is a big 50amp fuse to check and the fuse holder for it likes to corrode inside as well, it can be a real bugger to get to sometimes. While your in there check the connections on the alternator and starter as well, both are common problems.
Power for the control panel runs like this: Batteries --> APU starter --> APU alternator --> power post in black box --> control panel

 

Yes, most any auto parts store should carry them

 

View attachment 77742 There is your fuse that could be the one you r lookin for. Had same problem, and it was easy to find, just on the top of the batteries, it is inside plastic cover holder, and it is red. Hope it helps.

 

Sorry, i guess I do not know how to post the picture here, but it shows when I click on the attachment.I ll try again, see if this works. View attachment 77748