What would cause my car stereo to lose power immediately after installation?

I recently purchased a 1998 Jeep Grand Cherokee. I took the "Dual" stereo and Sherwood amp out of my old Jeep and put it in the newer one. I had everything hooked up, it was jamming.... for about 10 seconds, the Amp hard wired to the positive on the battery and i tried to put the stereo back in it's hole in the dash and i lost power. I have played with and rewired every wire that is coming out of the dash. I replaced the radio fuse (which was blown). I can get power to the amp alone, just not the radio. It seems like there has to be a short somewhere, but i can't for the life of me figure out where!