I think I might have toasted my amp...

chevyguy

Member
2013-03-04 10:36 pm
I have a 2004 Wrangler with a Pioneer DEH-X7500S head unit, Polk MM651 speakers, and a Rockford Fosgate Punch 210s amp. I had to do some welding on the Jeep yesterday (with a crappy ground too boot) and I forgot to disconnect the battery or unplug the audio.

When I started it after welding on it there was extremely bad alternator whine coming through the rear speakers. I turned the volume off and it did not change. Unplugged the amp and it went away. Plugged the amp in and disconnected the RCA cables and it went away. It does not happen with the engine off with the key on accessory. The front speakers are just some Polk 4x6's driven from the head unit and they still work fine. So it looks to me like something on the input circuits in my amp got fried.

Everything worked fine before I welded on the Jeep.

Would a ground loop isolator help out at all, or did I just send an old friend to it's grave?
 

chevyguy

Member
2013-03-04 10:36 pm
I checked the head unit and the amp. Head unit is fine, amp has 977 ohms on both inputs. That page only talked about head unit outputs but I'm guessing the same theory holds true for amp inputs. I have a very basic general knowledge of DC circuits but I've never had to do any real work on them. As a mechanic it was always check for power, ground, and communication then replace the bad part (whole assembly) or wire. I'm open to any and all suggestions as to where to go from here to repair my amp.