Greg: That is where mine was, behind the little door.
I had a wake-up call last year when I opened the door and found a "gaggle" of ants inside the rim. So I tore out the door, filled the hole with a spare piece of
fiberglass, epoxy, etc. Shaped it, sanded it, and painted it with Brightside and it is whole again.
Then I built a plywood box, fit it underneath with a spring-loaded door, routed the cable through the floor and coiled it into the box. The hole for the cable through the floor was just big enough to pull the cable through, and with some sealant around the cable was able to thumb my nose at the ants attempting to get in. Cleaned up the look of the trailer too.
By the way, if anyone needs a copy of the manual and preparation guide for a 2000 (or thereabouts) Burro 17' just drop me an address and I'll send it off to you. I just printed up some.