in my car i have had a 500w amp powering 2 10s for quite some time now but the other day i added a 100w amp for my 6x9s cause one of my deck channels stopped working but now there is a high pitched buzzing sound which usually means a bad ground so i bought some new stuff, ground distibutions block, 4gauge to a brace under the antenna behind the paneling, i sanded down all the paint till i got to metal and got a ring terminal and bolted it onto the brace. from the amps i have 8 guage to the distribution block. i ran a 8 guage wire from one of the spots on the dis. block to the negative battery terminal and i added a 12 guage wire from the headunit ground to that wire that goes to the battery that quieted the sound but its still there. when i unhook the small amp the noise is gone but i really dont think theres a ground issue i think its a problem with the amp. its a crappy old majestic 252. One of my friends said it might be from the ground being too close the power antenna motor, anyone have a better ground spot?

 

I dont know if this helps, but in my integra, between the two back seats there is a metal bar that already has a hole and is perfect for grounding. It possibly could be the amp. Make sure that u scratched the paint and everything and your connections are strong. Good luck

 

A ground loop or alternator whine can be distinguished by the pitch changing with the motor RPM. If it is a constant sound with no change, then it would be a bad amp, or a bad channel.

 

A real good ground spot is were your bolt goes for your seat belt but if you don't hide the wiring good enough it will look tacky as hell.

 

to rule out bad ground, use your DMM to measure it.


set the meter to impedance, or resistance ( the upside down horse shoe)
take the negative terminal on your meter, put it too the negative on the battery.

take the positive terminal on your meter, put it too the spot you wish to test.

the closer to Zero the better. try finding a spot that is less than 1 Ohm, and it will rule out bad ground, in your situation.


good luck.

-d-

 

I had the same problem, and it drove me insane. Then I turned down the gains and turned up my h/u problem disappeared.