I'm in the middle of installing an AVIC-D1 and a couple amps in my G, and have run into a problem. At some point inbetween hooking up the speakers to the amps, I've developed a low but audible "ehhhhhh" sound when the radio is on and one of the car doors is open. if I open both its gone, the same as when both are closed. I know for a fact that it did not do this when I only had the front right speaker hooked up with nothing else, so it wasn't there the whole time. My amp now also creates multiple pops when the radio first turns on and off, which it did not before the problem started. I've checked over the grounds to make sure they were all attached tightly, anyone have any ideas what else I can check out? The sound quality is excellent (no hum or hiss what so ever) when the doors are shut or both open, so I'm assuming it must be something with the d1? Thanks in advance for any advice.

Short info on the system:

- new power cables run up pass side
- rcas/ gps run up left
- both amps and a cap all share one ground in trunk (problem?)
- radio ground is attached to the metal guard on the driver's side under steering wheel
- have tried unhooking all speakers sans FR and problem persists

 

Been messing around some more with the car during work... the noise is coming from the lights in the car. If I turn the over head lights off, the hum dims as the the orange light around the ignition key slot also dims. Plus, turning on the headlights magnifies the sound by ten times. I haven't dared to actually turn the car on with my dash all torn apart, but I can't imagine it'll get any better. The rca's have 2 Scorche ground loop filters attached to each set, but it's not helping.

 

Ran a new set of RCA's from the HU to the amps, noise persists.
Tried directly grounding the HU to the negative battery terminal, noise persists.
Checked to make sure the inline resistors for the ACC and ILL wires were good.

 

A few questions if anyone can answer:

While the noise doesn't sound like a typical ground loop hum, I've decided it must be something along those lines. I hooked up a speaker to the internal amp on the D1 and have zero noise, and also ran my ipod thru the 4 channel amp in the back and have zero noise, so it seems to only happen when the 2 are connected together. Would running the ground from the HU back to the where the 2 amps and cap are grounded make a difference? And even though I tried a second set of RCA's that were laid thru the center of the car with no luck, would buying a pair of twisted wire RCA's be worth a try?

 

Solved my problem: I grounded one of the rca cables to the radio chassis and all noise is gone.