Memory Fuse keeps blowing as soon as contact is made.

I recently bought this van. Nothing worked while the car was off or in ACC position. When in the ON position most everything worked. I still did not have a radio though. I took it to the dealership to take care of a couple of things covered by recall, (whaddyaknow the horn, cruise control, and airbag worked again). Then I replaced the Body Control Module, and found that the Memory Fuse was bad and replaced it as well. When I connected the battery and turned the car to ACC, the radio worked, I had odometer readings, and it was working the way it was supposed to. I started driving down the road and then the radio went out. I pulled over and sure enough, the memory fuse was blown. I put in another (car was off, but the battery was connected) and it blew before I could get it fully seated. What could be causing the overload for the memory and how can I fix it? I would be fine with the ACC position not working, but I'd like to have my radio.