I found the univolt. I was underneath the bath tub. I havent plugged my trailer in since I brought it back from Florida. ( I am kinda of afraid to right now). There is a closet next to the bath tub and a really small access panel. What I found was a blue box that says "Airstream Univolt" with a small panel that opens up to the fuse panel. Some of the fuses are missling and there are a few wires that just hanging there. but inorder for me to get the univolt out I think I need to remove the aft wall out from the closet. The Univolt is bolted to the floor. I think the battery box is on the curb side back aft, but when I opened it up all I can see is two small holes in the plastic. So I guess I got my work cut out for me. I am not that electricly inclined.
I found the service manual for the trailer but wouldnt you know it the only page missing is the one for the Univolt. The manual is in pretty bad shape. It is falling apart and looks like something has chewed it up. <Sigh> I will let you know once I strat doing some more digging and searching throughout the trailer.