I need help with Alternator whine

DryHeat · 09-27-2004, 09:15 PM

I installed four new speakers and a used amp this weekend and everything sounds great...except for the alternator whine. I just turn the stereo up more and it's fine, but my wife wants it fixed.

The whine can be heard in all four speakers, but is much more noticable in only one. I did move the ground location to no avail. What would be the most common installation problem and/or what trouble shooting tips could you all give me?

Humbley yours,
Jonathan

adjmcloon · 09-27-2004, 10:10 PM

I've got this going on ever so slightly as well. I grounded the amp to the battery, and the head unit to the chassis. Short of grounding the head unit to the battery as well, I don't know how to get rid of it. If anyone has any ideas, let's hear them!

Sammy Sandbag · 09-27-2004, 10:50 PM

These are helpful:

Chassis Ground info: http://www.bcae1.com/ground.htm

Ground Loop Isolators info: http://www.bcae1.com/ground.htm

Audio Troubleshooting (scroll down for section on alternator whine): http://www.bcae1.com/ground.htm

gtbigup01 · 09-28-2004, 06:44 AM

Try rewiring your signal wire and the power wire, make sure that they dont run down the same side of the truck. IE if you run one down the left side (whichever) make sure to run the other on the opposite side of the truck floor. That should help.

adjmcloon · 09-28-2004, 08:17 AM

My rca's and power are separate. Are you referring to the amp turn on signal wire?

After reading those links it seems to me that the best thing to do would be to just run a ground wire from my head unit to the battery. At that point both the head unit and amp will be grounding on the same circuit.

Dry Heat I'll try it and let you know. This is a small problem as the whine is barely audible but it's annoying nonetheless.

gtbigup01 · 09-28-2004, 10:24 AM

Yes I was refering to the amps rca cables. If they are separate from the power wire there are a few other things to try.A cheap way is to install a noise surpressor, since engine/ alternator noise can be difficult to diagnose. To many variables for me to list here, any stereo store can tell you all the things to check, sometimes noise has to do with something simple as quality of rca cables, twisted pairs are claimed to be least proned to attract noise.

smoketitan · 09-28-2004, 12:16 PM

I told you all so, and no one wanted to believe me that the alternator is not as strong as we think.

I am having mine benched tommorrow at Nissan as I get the whine when I have my two amps wired up. when it is only 1 amp I cant hear the whine. I ahv moved my ground all over the place--and have determined that it is 1) the alternator has some weird ground issue--cant pinpointit yet) and second the stock HU ground are not grounded to the chasis casuigna ground loop problem. I am almsot sure if you can find a way to groud the HU to the SAME location as the amp the noise will remove itslef. I and a local tech checked mine out, and we were able to eliminate it by grounding the otput rca cables to the same ground as the maps--which proved our hypothesis it has something to do with the HU ground

Mine started after some nissan tech blasted my stereo with at the gains/bass maxed while the car was not running--dumb huh--they blew two sets of speakers and destroyed the amp internal ground---which is why I think I have some ill alternator issue also

also try and make sure your ground wire is the same thickness as your power wire, but at least 4ga

I may try the HU grounding to the battery also

adjmcloon · 09-28-2004, 02:11 PM

Thanks smoketitan.

I'm running 4ga power and ground to the battery. I've got to install the SWI-X thing to regain my steering wheel controls this weekend (along with my XM satellite radio) and so I'll go ahead and ground the HU to the battery.

Any Armada owners installed an aftermarket satellite antenna? Where did you run the cable? I'm really dreading the install...

smoketitan · 09-28-2004, 02:14 PM

how many amps are you running? and what head unit did you buy?? I think I am going to get a 860mp pioneer

Hatchman · 09-28-2004, 07:13 PM

Most common ground noise is from using an aftermarket stereo with the stock ground. Always seems to have noise. Best to ground the stereo directly to the chassis.

To make a long story short, the last truck I had, in order to find the noise, I changed out the stereo, the amp, bought 2 kinds of ground isolators, and moved my amp ground to 5 different positions.

It was all solved by grounding the headunit to the chassis, instead of the stock wiring harness ground. Learn cheap from my mistake. Grounding the HU to the battery sounds like a good idea.

Hatchman · 09-28-2004, 07:16 PM

Quote:

Originally Posted by adjmcloon

I've got this going on ever so slightly as well. I grounded the amp to the battery, and the head unit to the chassis. Short of grounding the head unit to the battery as well, I don't know how to get rid of it. If anyone has any ideas, let's hear them!

I always heard you were supposed to ground the amp to the chassis as close to the amp as you possibly could. Correct me if I'm wrong.

I also heard any high voltage lines should be run away from low voltage lines. In othere words, no RCA amp cords next to speaker cords.

bestatchess · 09-28-2004, 08:18 PM

I thought that the HU was grounded to the chassis by the radio bracket?

DryHeat · 09-28-2004, 08:18 PM

Well I tried regrounding the head unit. No luck. My wife is going to have to deal with the whine if she wants to drive my truck this week! *Hint* I'll drive it and suffer

This weekend I'll pull the seat out again and re-wire some stuff...ughhhh. Next time I'm going to the $1 install place and buying some new equipment. I'm getting to old for this stuff.

Jonathan

bestatchess · 09-28-2004, 10:13 PM

An interesting article on alternator whine:

http://www.diysubwoofers.org/project...f/alternat.htm

adjmcloon · 09-29-2004, 02:26 PM

Smoketitan,

I'm running a Soundstream 800.5 for my whole system. 4ga power and ground to the battery. My hu is a Premier DEH-p960. It's currently grounded to the chassis but I'm going to wire to the battery this weekend.

Dryheat, did you ground your hu to your battery? Other than bleedover I don't see how there could be any noise if the hu is grounded the same as the amp. My rca's are all triple shielded and are run on the opposite side of my Armada as power.

Thanks for the article bestatchess. So from what I took from it if we were to split the hot and ground signals between cables that would essentially eliminate the noise? In other words, one rca cable pair for hot and one rca cable pair for ground?