Where would be a good ground location...

[SFBerto415]

I seek help fellow TahoeYukon owners! I am hearing that alternator whine that comes through the speakers when accelerating. I know it has to do with ground connection, but here is the thing: I do not have an aftermarket amp installed in my truck.
(My signature states what I have installed in my truck as my audio entertainment system.)
I have taken it to an audio shop and they recommened ground loop isolators...these GLI helped but didn't eliminate the noise just softened it a little bit, but at higher volumes the noise is very obvious.
Today I was fed up and snapped off the dash and a shell that is attached by two screws under the steering wheel and found a ground wire that the audio shop used to ground my electronics.
Obviously this is not a good ground connection or maybe it is???? This is where you knowlegable people come in.
Should I unscrew this attempted ground connection and screw it somewhere else? Should I add more wire and then run the wire to the negative car battery terminal? Should I cut a small opening in the carpet under the driver pedals and screw it there? I need help folks, this noise is gonna drive me insane and I have a long trip coming up this weekend and it will really suck...

 

[sdgd711]

Are you getting noise on everything (ie FM radio, CD player) or is it just on the add ons (Sirius, Bluetooth, headrest monitors)?

Alternator whine is not always necessarily from a dirty ground or a ground loop, but it's definitely a possibility. I have found that the driver side kick tends to be a clean ground. There is nowhere under the dash that I have ever found to be a good ground. The way to find out if the spot you want to ground something is good is to set your multimeter to resistance (ohms). Put one of the leads on the main ground under the hood and take the other and apply it to a paint free surface in the truck where you want to ground it. The meter should read 0.0 something if it is a good ground.

If you don't have a meter you can start with the following if it's a ground issue:
-Common ground all of your components in the drivers kick including the head unit, bluetooth module, Sirius module, DVD player and screens (if your getting noise on the headphones).
-Scrape the paint all the way down to bare metal (avoid using any kind of existing factory ground)
-If you have to extend wires to get them to a common point, solder them. Butt connectors and crimp caps can cause unwanted resistance.
-If you do have to extend them do not combine, for example, three 16 gauge wires into one 16 gauge wire. Run separate wires for each ground.
-When screwing into your ground point use a ring terminal for all the wires (don't just wrap the copper wire around the screw), a self tapping screw, and a star washer (metal gripping washer).

Other common causes of alternator whine are:
-Unshielded (or sometimes shielded) signal cables running near something that is putting off noise (ie. BCM, ECM, airbag module etc)
-Aftermarket crossovers being placed too close to a factory module that is putting off noise. I had this happen to me once and it took me a half a day to figure it out.
-A bad component in the system (possibly a loose solder joint on the board).
-Bad signal cables

Ground loop isolators will work sometimes, but they can also make it much worse. They are really just a temporary fix for the real problem. Hopefully this helps, let me know if you have any other questions.

 

[SFBerto415]

Thanks for the info...it is very useful and very detailed. I did notice that all the componenta are all crimp capped together into one single ground wire. I will be running individual ground wires from each extra component and hopefully that should fix the problem...Thanks again sdgd711

 

[OmarR]

I had alternator whine on my system using the stock amp, but only on the lower 6 disc changer.

I added a ground loop isolator, and it did diminish the whine.

In the end, I ran 4ga from the battery to the stock ground that is at the bottom of the driver's side pillar. I also ran another 4ga from this point to the ground wire of the headunit, which I actually soldered.

100% of my whine went away. One of these days, i will get around to pulling off the ground loop isolator to see if my new grounds can do the job by themselves.

 

[sdgd711]

Thanks for the info...it is very useful and very detailed. I did notice that all the componenta are all crimp capped together into one single ground wire. I will be running individual ground wires from each extra component and hopefully that should fix the problem...Thanks again sdgd711

No problem, hopefully you can it fixed before your trip. Let us know how it works out.