hey whaddup every1. i have a 400 watt rms rockford fosgate subwoofer running off a 400 watt kenwood amp. when i put the volume up, EVERYTHING in the car dims like crazy. i used to have a honda and it used to dim to but this dims even more than that i think. its horrible looking. i had a capacitor on my old system in my honda but that didnt help as much as i thought it would. any suggestions?!

 

Sounds like something isn't grounded right which is drawing power.

 

i have the ground from the amp bolted directly to metal on the car. anything else?

 

Is it going to the painted portion of the metal or down to the bare metal?

 

i sanded the paint so its straight metal

 

Your problem is that the amps are drawing more current than your electrical system can supply. Try adding a 1.0 farad capacitor to your system. This will help to regulate the current draw.

 

get a new battery....1 400 watt amp shouldnt do anything to any cars electrical system if everything is working correctly. I have 1100 watts RMS and I have 0 problems. My capacitor never reads below 13 volts so it really isnt even needed.