[TreeFrog]

okay it could be a few things.

make sure your wireing is 4 gauge, and that you fuse can support it. also make sure the battery connections are free of corrosion on the positive and negative sides. make sure the alternator is hooked up right

the cap should help solve the problem, to hook it up, run the power cable directly to the cap, then run a power cable from the cap to the amp. run the ground from the amp to the cap, and from the cap to a GOOD grounding souce. the BEST gound is running a cable from the cap ALL the way to the battery ground termanal. newer cars don't have as good as a frame and relying on the frame to complete the circuit to the battery is not a good idea. with that kind of power you can't just ground it to any old place. make sure that the power and gound cables from the amp to the cap are no more the 3' in length.

also when you run power and ground on the same side negate each other and form a magnetic shield. so putting the RCA and remote wire on the same side will sheild them from interferance. if the power and ground are also on the same side.

best thing to have is a volt meter on the cap, and making sure the volts say above 12. i have a Rockford power 1000db with 1000 watts RMS. is your cap 1400 watts max or rms? my lights STILL dim because with this kind of power you need a 5 farad capacitor. especialy with the car is only idleing.

any other questions please ask, i'm very knowledgeable about car audio.