Here's some history. I had a Pioneer (don't have the exact model in front of me) that got stolen. I have the Eclipse 3640 Amp. When I had the new tuner installed (the next model up from the one I had), I was told there was no power from the amp. All I had was the back speakers working. Now, occasionally, I will hear the amp pop. Recently, I'd have power from the amp until I tried to turn it up. Anything beyond about 19 would shut the amp down. I'd have to turn the truck off and restart it to get the amp back. Once, I had the amp but muffled sound from the front speakers.
Anybody have any clues what may be happening? I've checked all the connections at the amp and they appear to be fine. The RCA cable was replaced with brand new fairly heavy guage. I haven't opened the unit up to look but the fuse on the outside appears fine.