So I got all my stuff in the mail and installed it this past weekend. I am now getting alternator noise out of my speakers. I ran the power cable through a plug under the driver's seat to the bottom of the truck and then to the engine compartment. I ran the rca jack under the carpet around the driver's side door frame. I know you aren't supposed to run the rca's and power cable together for this very reason, but I thought the seperation of the two cables by the floor would have been sufficient enough. I also tested the ground just to make sure it wasn't a bad connection by using jumper cables from my battery to the ground lead out of the amp, and was still getting the noise.

Did I do something wrong? Is this annyoning noise ever unavoidable? What are my options for diagnosing the problem and fixing it?

 

If i'm understanding this correctly you ran your power wire outside the truck? Please tell me you protected that with PVC or conduit of some type? Loose wires are a bad idea underneath a vehicle. IF you didn't ignore that paragraph.

You check your ground, are you RCA's shielded? Is your HU properly grounded? Usually alt whine is introduced through an improper ground. (correct me if im wrong)

 

The RCA's are shielded. I bought a set of Monster Cables. The HU is grounded through the wiring harness. Should I pull the cd player out and check it?

 

I guess that wouldn't hurt to pull out the HU, not sure how to fix the problem though just yet...have you checked the speaker wires all correctly hooked up and not grounding out? Could be a bare speaker wire touching metal somewhere that is causing this.

 

The noise changes as the pedal is pressed. I would think a groundedbare speaker wire would not cause this? I think when I get home I will use my jumper cable ground check on the HU real quick to see if thats the issue or not. If that's not it, I guess I'll just have to start bypassing components until I find the culprit!

 

Yep...alternator whine....gota be a bad ground somewhere. I would re-ground the headunit first, as it is the starting point for everything in your system.

 

If you're certain you have a good ground on everything, try a noise filter. They splice in line with the switched 12v lead and have their own ground to chassis. Worked for me when i couldnt otherwise kill alternator whine.

 

Ground loop isolators go inline with the patch cables....
Since were on the topic, here is a GREAT read for everyone http://www.epanorama.net/documents/groundloop/

 

That's for AC current in residential/business situations, so the whole first part about grounding for faults is irrelivent, but the principles in the ground loop sections hold true for car audio as well. So, still a good read.

 

ok...im stumped on this whole alternator whining problem. I checked the HU ground, it was ok. I checked the amp ground, again, it was fine. I unplugged the RCAs from the CD player I still get the noise, so I assume its the amp, or amp area. Near the amp, I have my Sirius tuner and (2) Xovers installed. They are inside the compartment under the jump seat. I unplugged the sirius tuner, with no change. I removed the tuner, no change. I tried unplugging the remote lead from the HU and the amp, and using a jumper from the amp's power to remote, nothing.

Am I missing anything? I'm about to the point of taking it to a local car audio shop and paying for someone to re-wire, troubleshoot, fix, break, whatever...so I can get rid of this noise.