racing20

iTrader: (1)

I have a '92 RS. It had some cheap CD deck in it when I bought it. I had no problems with it. Then I got the XM Satellite in it. Hooked it in through the RCA cable input. Then when I used the aux mode on the deck with the XM, I get alternator noise whining in the speakers. It changes pitch as my engine RPM's change. It did not do it on the CD player or the radio. I also have an Alpine AMP and 2 12's but the noise was in all the speakers. I got rid of the POS deck and got a better one by Pyle. I hook it all up and now the engine noise is ALLWAYS there whenever it's turned on. Does it on the XM, CD and radio. But it's crystal clear while the engine is off. It's very noticable at low volumes and very anoying, but I think it stays at a constant volume cause I can crank the radio and drown it out. I bought an in line power line filter that is supposed to stop the engine noise in the radio, but it did absolutely nothing. I've unplugged the RCA's to my amp and XM but the noise is still there. I've read somewhere that older cars alternator was grounded to the chasis and so is everything else on the car so that's why the noise comes in. Ever heard this theory? I haven't tried grounding it anywhere else cause I figure if that's true, then what would it matter? It's grounded now throught the factory radio wiring. I found one post on here (https://www.thirdgen.org/techbb2/sho...ht=radio+noise) about it, but the guy never found the problem. Someone also said he ran a ground wire from the deck to the RCA cable from his amp and it fixed it. I'll try that tomorrow. Any quick try me fixes that anyone has, I'll try.

Gummie

The reason why you can't hear it through your subs is becuase they're not playing that frequency range. I didn't know the amp I was using to drive my subs was making noise until I hooked it up to my comps. A new amp solved the problem.

I've got a question for you: are you running an amp for your main speakers as well or just your subs? Alternator whine through the deck's internal amp is pretty uncommon.

Here's my thread: https://www.thirdgen.org/techbb2/sho...ighlight=noise

NEEDAZ

Make and model of the HU and amp?

racing20

iTrader: (1)

No, I'm not running an amp through any other speakers, just the 2 12's. It's a Pyle HU CD42 and I'm not sure of the model number of the Alpine amp.

stitchop

That is true not just for older cars, but for modern cars and trucks. the ground side of the 12V system is the metal frame or chassis of the vehicle. Look at the battery cables. The Neg. side has a cable going to the engine, and to the fender. The engine has a braided cable going to the chassis. Every circuit ends at a metal grounding point on the body.

Most of the whining noise is prob coming from the ignition. Cheaper head units and other components are worse about producing the noise. If you think it is the alternator, just unhook the wires from the alt, start the car and listen for the noise, if it is still there, it is not the alt.

racing20

iTrader: (1)

Well, I think I found the problem. When I unplug my RCA input for my XM, the noise dissappears and is crystal clear with the radio and CD player. Hook it back up and it comes right back. The power for the XM is the lighter adapter type, not hard wired. Maybe I'll try an RCA noise filter and see if that helps.