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Forum nameAudio, Alarms, AV
Topic subjectAlternator Whine
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i10&topic_id=4062
4062, Alternator Whine
Posted by djtrickee, Oct-01-02 12:03 PM
I am getting some alternator whine whenever I turn on my headlights. I ran the 4gauge down the left side of the car and the RCA/Speaker wire down the right side. I also sanded and drilled a new ground point for my amp and headunit and DVD player. Used high quality cables all around... Any ideas where it could be coming from? And what the heck can I do about it? It drives me nuts!!
Thanks-
Chris b.
4063, RE: Alternator Whine
Posted by 95_ESi_Person, Oct-01-02 01:00 PM
Any alternator will whine when a hard enough load is put on it. Stereos, many many lights, any large electrical load placed on it will cause it to whine because it is working harder.
4064, RE: Alternator Whine
Posted by djtrickee, Oct-01-02 01:35 PM
I guess I should clarify what I mean... I can hear the whine which changes in pitch when ever I hit the throttle. It comes through the speakers.
-Chris b.
4065, RE: Alternator Whine
Posted by audiophyl, Oct-01-02 03:34 PM
Nine times out of ten, alternator whine is caused by the power wire touching the rca's. In your case, you did good by running the rca's down the passenger's side of the car. The driver's side usually contains the power wires for the electrical in the rear of the vehicle, which can lead to noise.

I would double check the routing of your wires. I'd be willing to bet that your rca's and power wire are touching just before they enter the amplifier. This is a common problem when installing systems, since some amplfiers put the rca's on the left side.

If that isn't the case, swing by your local Circuit City (keep in mind, that's where I work) and pick up a ground loop isolator. This piece just might be the answer you are looking for. They don't always work, but may be worth a shot.

Good luck to you and let me know if I can be of further assistance.

See you in the lanes! :thumbsup :thumbsup :thumbsup
4066, RE: Alternator Whine
Posted by djtrickee, Oct-02-02 02:04 AM
Thanks. I will go back and recheck my wiring setup. I tried to be extremely careful in my cable runs, but I guess when the all arrive at the amp they might be touching. Also could that whine enter the wiring from the RCA's and power/ground of my DVD player? It is an indash DVD player and the RCA's from it run to the deck and the power feeds off the head unit supply and it is ground on its own bolt. I ask because it seems to be a louder whine when I use the DVD player.
Thanks again,
Chris b.
4067, RE: Alternator Whine
Posted by a_miller_76, Oct-02-02 02:28 AM


Here's one for you Audiophyl....I have the same problem. No amps, no rca's, no power wire. My head unit whines whenever I use my headlights...same as his ;) I've tried reground, different power sources, bla bla bla...finally said fq it!
4068, RE: Alternator Whine
Posted by SPL_Eclipse, Oct-02-02 07:49 AM
wow...this is a really interesting problem. heres my only thought: try isolating the housing of the CD player from going to ground (i.e., dont let the metal casing touch the metal of the car). to test this, just take the headunit out and hold it in your hand/lean it on a pile of rags/etc. while you turn on the lights and rev the car.

i would normally say that its a bad ground, but if youve tried several locations and it still happens, i dont know what else it could be. you dont have it grounded to the cig. lighter ground do you?
4069, RE: Alternator Whine
Posted by audiophyl, Oct-02-02 03:27 PM
OK! Here's my suggestion. Possible gound and/or possible power.

Alpine recommends on all of the 60x4 headunits to run the constant wire directly to the battery. These headunits pull so much current, that the stock wires for constant do not handle enough current. I would recommend using at least a 12awg wire and perferably a 10awg wire.

Our radios have to be grounded seperate of the factory harness. I would check to see that you indeed have a good ground.

One other suggestion, do you have the infinity system in the car? This factory option has an amplifier, which could be introducing the noise. If so, I would recommend bypassing the amp and running wires directly to each speaker. Yes, I know the wires are hard to get through the door boot, but it will sound better once it's done.

Here's another thought that I just had. You have components. Where are the crossovers mounted. If they are in an area in which they can come in contact with power wires, this too can introduce alternator whine.

Good luck to you!

4070, RE: Alternator Whine
Posted by XtremeRS, Oct-02-02 10:57 AM
Alternator whine is caused by a ground loop in the wiring system somewhere. You did good by running on opposite sides of the car. Ground loops can enter almost anywhere, at any componet. Having many ground points on your equipment is a perfect cause too. Try and have all your grounds as close to eachother as you can. Anything up front you have, ground that together, and the amps in the back, ground that to baremetal, with a bolt. Also, try cleaning the battery-to-chassis ground at the fender, be sure its on bare, clean metal. If the noise is still there, try using a "twisted pair" type of RCA connector, as these will null out any possibility of induced noise picked up along the run of the RCA cables. Do you have an amp going to your fronts and rears? If you do, run the car to make the noise, then disconnect the rca inputs the amp that runs your fronts/rears. If the noise goes away, then the ground loop is entering through the RCA, most likely at the head unit, by bad grounding. If the noise is still there, then its coming in through the power wire, but thats less likely. Also, a WEAK or BAD battery can let alternator noise in to the power wire for an amp. A good, fully charged battery will itself "filter" out most alternator noise. I have a yellow top battery, 3 amps, and power wire and RCA down sep sides of the car, and a bolted ground in the back for the amps, and NO noise whatsoever.
4071, RE: Alternator Whine
Posted by loudgs, Oct-04-02 03:10 AM
dood, I had the same problem, but one thing you might wanna check, my Focals had extremely bad alternator whine and I used ALL top of the line stuff to hook it up, twisted RCA's that cost me $120 and the such, it all turned out to be that I didnt properly solder the dropdown from behind my head unit to the wires goin from the amps to the speakers, make sure you have DAMN good soldered connections, no crimp on or twist on connections, solder dem bad boyz