hello im new here my name is chad i have a sony xplod HU kicker 12 and an oldschool targa hexfet 500 watt amp in my 93 civic 4 door well when ever i turn my car on my sub starts thumping moving in and out about 2 or 3 inchs doesnt look too good but if i wait it will quite down and not move as much. now when i make any changes to my radio change tracks on my cd change radio stations any thing it will start doing it again untill music begins to play then it will stop. when i turn my car off it thumps too

what could it be im so confused

and when im listining to a cd and i turn the volume all the way donw it sounds like thunder in my trunk

Edited January 13, 200817 yr by kermit5327

You need to start by isolating the problem.

First, disconnect the RCA's from the amp. Do all the signs you just told us about still happen? If they don't you have a problem with the RCA's or the Head Unit. If the problems are still there, its the amp. Moving on...

Second, plug the RCA's back into the amp and unplug them from the Head unit. Do the problems still persist? If they don't, you can rule out the RCA's being the problem. Its the Head Unit.

Report back here.

it is only when the rca's are pluged it but i think i might have found the problem im running my sub bridged but i only have one rca hooked up to my amp because the other port is messed up on my amp im trying to find a place that will fix it for me

i have had that happen before .. it was the rca's the ends was bad goin in to the amp an the rca's did connect good to the amp...

i think thats part of the problem here

keep the RCA's plugged into the amp and unplug them from the HU and see what happens.

when i unplug the rca's it stops no matter were i unplug them from but i figuered out what the problem was see the right channel on my amp doesnt work so i cant plug the rca into it and i had my sub bridged on my amp so i hooked my sub up to just the left channel and it stopped makeing the sound and is working just fine now

That makes no sense, but ok.