Jim,
When I bought my 77 Excella, I had a similar problem and found that I had 12v
coming into the fuse box but not going through the grid to the individual
circuits that have seperate breakers. In my case, it seems that the rivets or
connectors that assembled the metal fuse grid had lost their ability to transfer
the current. I found that if i took a jumper wire from incoming power feed
to individual circuits, I would get power. My fix was to seperately wire an
in-line fuse for each circuit to eliminate the actual fuse grid.
I believe you are fairly close by in north Atlanta. If the trailer is here,
I would be more than happy to look at it with you one evening. Email
privately is you need a hand.
John