Hi all, I just picked up a Kicker 600.4 amp, but seem to be having a problem with it. with the car running, I get the dreaded whine from the alternator. But if I pull out the rear RCA's the buzz goes away totally. if I pull out the front RCA's the buzz becomes 10x worse. Now if I do the same thing with the car not running, with both sets of RCA's in, it plays fine, maybe a slight humm. Now once again, if I pull off the front RCA's again, it makes a horrible loud buzz, but again, pulling off the rears run with no annoying sound. Ive tried swithcing RCA's front front to rear, switch the speaker leads as well. The power cables and RCA's are no where near each other as the battery is in the trunk under the floor. The amp is solidly grounded direct to the battery, and the head unit if grounded to fresh metal in the front. I tried to run another ground to the battery, still same thing, tried running a new and tested RCA over the seats, still buzzing. Anyone have any ideas what to do next? Thanx

 

how long is ur ground,,,,,,did u try grounding to the frame, instead of the batt?
how cheap are the rca's?
ground loop?
where is the power wire routed under the hood?
start with that!!

 

RCA's are not the cheap ones. Ive tried grounding to the frame, and there is no power wire under the hood. Its a 2009 charger, so the battery sits under the trunk floor with the spare tire, so the ground wire is only about 3 feet long. Im guessing that if it was a problem with the RCA's, the noise would switch between the front and rear channels as I move the RCA's between the 2, but it constantly stays in the front no matter what RCA's I use.

 

You've done a decent amount of troubleshooting. So as I read it, regardless of what the RCAs are connected to up front (front or rear) if you plug RCAs into the rear inputs of the amp, and especially if they are the only RCAs connected to the amp, you have noise. Conversely, if you have only the front RCAs on the amp connected, there is no noise.

Is that right? If so, you've pretty much singled out the amp as the problem. Either use the front inputs only, assuming the amp has an input selection switch, or get it fixed.

 

^^ x2...if you can get another amp to try...i'd do that to verify, but given that 2 channels are good and the other two are not with the same input...seems pretty clear that those inputs and/or related circuitry have a problem.

 

took it in and its deffinately the amp. Even wih just 1 RCA in, all 4 speakers can be heard, so the signal is somehow bleeding through. Now to figure out if its better to repair it or replace it.