Car Stereos: amp makes a thump and when touched plays static, rca plugs, rca jacks

Question
QUESTION: I brought my Grand Cherokee to the shop for trans problems with the radio and amp working and now the amp doesn't work right.  When I turn off the vehicle off i get a thump; and when i touch the amp I hear static through the the speakers.  Nothing was changed and don't know why they would mess with the radio.

ANSWER: jeremy,

That is a bit discouraging.  At first, I would think a ground wire was removed or bumped loose for some reason, leaving the amp with an open circuit.  After that, I was thinking perhaps your amp wire was connected directly to the battery without an immediate fuse, and they rerouted the power wire to a fused lead somewhere.  I would, definitely, try and get ahold of the guy that worked on your truck to see if they did change anything.  Hope this helps, Scott

---------- FOLLOW-UP ----------

QUESTION: Thanks for responding so quickly.  The amp and radio are wired correctly with a fuse near the battery and a 18" ground wire on the amp. I cleaned the ground up and changed the blue power wire from the head unit and no change.  I unplugged the RCA jacks from the back of the radio and heard a lot of feedback in the speakers.  As I touched or moved the RCA cord I could hear it in the speakers so I'm going to replace that and see what happens.

Answer
That sounds like a good plan.  The problem is definitely a short of some kind.  I have seen RCA plugs just barely touching the case of the amplifier cause overloading (static).  I just pulled the plug out a bit, and it worked fine.  It really is tough to troubleshoot.  You just have to check each wire, and be sure there are no worn spots or tight areas.  Sorry I couldn't do anymore for you, but it does sound like you are on the right track.  Good Luck, Scott