Ground Loop Noise: I'm stuck.

[Spaceboy464 10+ year member]

Ever since I added an aftermarket sub and amp to my car I was getting a ground loop whine. I eventually fixed it by connecting the speaker's common ground (there is only one speaker negative wire from the headunit to the OEM bose amp) to the OEM headunit.

Everything was fine until I installed an Avic D3. This weekend I ripped apart my audio system to fix this problem, but was not able to.

I tried:

• Grounding the common ground to the D3.
  
• Removing the sub tap I installed
  
• Completely disconnecting the sub and it's amp
  
• Grounding the headunit to another known grounding point
  
• Grounding the common ground to another know grounding point
  
• Grounding the RCAs to another known grounding point
  
• Any combination of the above
  

Eventually I took out my wiring harness and took off everything except the basics to run the D3. This didn't help so I then rebuilt the harness, which did not help. I did notice that I could unhook all but one speaker and have the noise get louder and come from all of the OEM speakers. The noise is there with the car in accessory or if the engine is on, it will vary with my RPMs.

Some people were suggesting my D3 is to blame. What can I do to fix this annoying problem.

One thing I noticed is that I could get the noise to become very loud by touching the ground from the factory and D3 harness to another ground point and then disconnecting the lead to the D3. If I unplugged the OEM amp the noise went away.

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[quest51210 10+ year member]

bypass the factory amp alltogether

 

[Spaceboy464 10+ year member]

bypass the factory amp alltogether

May I ask why?

 

[quest51210 10+ year member]

to get rid of the noise...is that not what u asked for?

 

[casper97ta 10+ year member]

x2^^ you said when you unhooked the factory amp, the noise went away. So eliminate the source of the noise.

 

[SlamSession 10+ year member]

Might be the your car's alternator, how old is the alternator ? Has it ever been replaced ? Maybe it's time to get a new alternator. Do you have a crossover in your system ? Also the Gain knob on your amp(I'm not sure if it has one) if the Gain is turned up all the way it may cause additional noise to come out through your speakers.

Another thing that might help is if the amp grounding is clean sheet metal, make sure it's not like a tack welded area, in order to get a good clean ground. You might have to take some paint off of where you're going to ground the amp.

 

[SlamSession 10+ year member]

Spaceboy, I didn't read the all of your description the first time. The second time I read it, I see that you put the when the engine's RPM's increase, the whine in your sound system also increases. Well, that is your alternator my friend. As you may already know the alternator is hooked up with a belt to the pulleys of your engine. So whenever you increase the engine's RPM's the RPM of the alternator also increases, thus increasing the "whine". I think Stinger(they have website) they sell high output alternators that are chrome and stuff. I'm not sure if streetwires sells alternators, but you should check out their websites.

 

[quest51210 10+ year member]

Spaceboy, I didn't read the all of your description the first time. The second time I read it, I see that you put the when the engine's RPM's increase, the whine in your sound system also increases. Well, that is your alternator my friend. As you may already know the alternator is hooked up with a belt to the pulleys of your engine. So whenever you increase the engine's RPM's the RPM of the alternator also increases, thus increasing the "whine". I think Stinger(they have website) they sell high output alternators that are chrome and stuff. I'm not sure if streetwires sells alternators, but you should check out their websites.

ur an idiot

 

[Spaceboy464 10+ year member]

to get rid of the noise...is that not what u asked for?

I was asking for clarification. Thanks though. So how would I go about doing that? I doubt they make a bypass kit for my car. Do I need to just run new speaker wire?

As to it being my alternator...I would hope not as the car is only 3 years old.