SsZERO

Last summer I put a nice system into my GTO, and while it sounds awesome I has some annoying alternator whine that varies in pitch with the engine speed.

I also noticed that when the system is running off the battery, I can hear what sounds like static on the speakers. If I activate any electrical device, such as the rear defrost or blower fan, I will hear feedback from those as a whirring sound. When the car is running, I do not notice any feedback from other electrical devices.

I am stumped on this one, and I have tried a lot of things with no success:

- Amp is grounded directly to chassis (no paint).
- HU is grounded via wiring harness to factory ground (also tried grounding it to chassis with no effect)
- Tried using several ground loop isolator products.
- Tried using inline power filters that go to the +12V and +12V BATT.
- Disconnected capacitor

Nothing above made any improvement at all, or any change for that matter. This noise is present only when the signal RCAs are plugged into my HU...otherwise there is no sound. This whine does not go away if the HU is turned off either.

Here are the relevent components of my system, and if anyone can help me fix this I would be very grateful!

HU: Pioneer AVIC D1
AMP: Rockford Fosgate Punch 8004
CAP: 1.0 Farad
BATT: Optima Yellow Top

ded71

iTrader: (7)

It is my experiance that alt. whine usually has to do with a bad ground. I know you said the ground is good, but have you tried it in a different location? Maybe a different gauge wire, or better ring terminals? Not sure if it will help, just a thought.

HiTechGent

THe noise is coming in thru the signal path. Not the power/ground paths. My guess is the problem lies with the RCA cables themselves. Remember, since amplifiers draw a considerable amount of current, you should not route your RCA cables close to your power cables. Also, you do not want to use cheap generic cables, like those available from Walmart or Radio Shack.

1BadAzzWS6

iTrader: (11)

Did you run your RCA's near the power/ground wires??? If so move them.

Also it does dsound like a bad ground IMO. Try moving your ground to a better location. Also make sure the ground area is sanded down and has good contact.

Country Boy

iTrader: (24)

Im with the RCA cables. Route them away from any power or ground wires, and try to keep them away from speaker wires also. Get some good name wires that are properly sheilded.

1BadAzzWS6

iTrader: (11)

werd...make sure they are decent wires with the proper shielding. I don't think alot of people realize the importance of buying good wires. Your local tweeter, best buy, or circuit city should have them.

SsZERO

I am using very good cables, and I did not run them next to any power or ground cables...so I am sure they are not the issue.

The only possibility i can see that ground would be a problem is if splicing a the ground wires for several devices together onto the one ground lead for the head unit. By that, I mean that I have my HU, the XM tuner and the PAC steering wheel control adapter's grounds all connect to the one HU ground on the harness. Is this causing too much resistance or something?

makoshark

iTrader: (3)

I had the same problem in my system. I grounded my headunit in the factory harness ground. I moved it and the whine went away. Seems that the factory ground there wasn`t good enough for the aftermarket stereo

SsZERO

Ok I wanna try re-grounding the HU...where is the best place to ground the HU? Should I worry about the length of the ground wire? I am thinking if I use a 10 gauge cable, that should minimize any resistance and prevent whine due to ground.

WantedRawb

iTrader: (2)

10guage is a bit over kill for just the head unit ground...but it wont hurt. what type of plug wires are you using ? and by chance did you ground any amps or anything to a seatbelt bolt? that can cause problems too...