got an anoying ZZZZZZZZZZ sound coming from my stereo even when the motor and ignition is off, power and rca wires are ran on opposite side of the car, 500watt amp bridged for 2-6x9s and 2-6.5s pioneer deck, good grond for amps and deck. what else to check?
I would double check all grounds. Make sure area is clean, check ground wires with continuity check. Dan
Could be Spark Plugs, Spark Plug Wires or Alternator causing the noise. I would try installing a inline noise filter on the power wire to the stereo.
it is just a hummm, even when the car is turned off. i pick up power from the starter solenoid post with a 2gauge wire, to a 1.5farad capacitor into a splitting block and to my amps, ground is to a bare metal spot i grinded on the rear fenderwell.
About the only thing I can think is that some other electrical device that is on at the same time is putting noise into the power line (noise would be present on all channels) or there is an internal problem in the head unit or amp (noise would probably be on just one channel of a two-channel stereo). Most head units and power amps come with pretty good power line filtering but sometimes you have to add more. Have seen already where the shielded cable from the head to the power amp was defective, didn't provide enough shielding. Have also seen strange ground loops that are only solved by grounding everything in the system to the exact same point, rather than to the car body. If the volume of the hum changes with the volume control the problem is affecting the head unit's preamp. If the noise level is continuous it's caused by something past that point in the system.
