ok let me give a bit of background.

I left my window down when it rained, my amp died.
about two weeks later i meet someone at work that is selling an amp.
I take it to my car to hook up to see how it sounds.
Error #1. I accidently touched the amp power wire to my pre-amp output wires from my stereo, made a click sound.
I went ahead and hooked it all up, no power going to amp. Stereo comes on, wont play any sound.
I disconnect the amp, then I try to turn the stereo on again. Lots of smoke comes from behind the stereo, I frantically disconnect my stereo but luckily no fire. the fuse is blown.
I checked the wires to my amp, none were touching the two pre amp wires from my stereo, so that would not be a cause.
I put a new fuse in my stereo, as soon as I plug the wires back into my stereo, the fuse blows, repeat process 3 times.
I take apart stereo looking for burns or anything. nothing.
I put the stereo back in my car, it starts up but still no sound. but their is lots of static coming from only the front right speaker.

Thats where I stopped for now.

 

Sounds like you fried your internal amp. This is a tough one, you might need to take it to a stereo shop and have them look at it.