Alternator Whine in stereo - 986 Forum - The Community for Porsche Boxster & Cayman Owners

mjstallion · 08-07-2007, 08:20 PM

I got my car stereo installed a few months ago, and in the last 2 weeks I've started to notice alternator whine as the revs go up.

I find this irritating since I went to a high end stereo shop and spent $1000 on installation (door,dash,rear speakers, amp, and rear cam) and I spent that type of money with the expectation that I wouldn't have any noise at all. The $1000 was spent after I went to a crappy installer who installed a lot of the stuff but did a terrible job, so it all had to be redone. Anyway, I have cheap RCA cables going from the head unit to the amp, and I remember the high end stereo shop telling me to get their $75 RCA's because it would make the quality better, but I didn't cuz I thought it was a ripoff.

I know when I go back there to get the issue fixed he's going to blame it on the RCA cables, cuz there's nothing else to blame it on, and because he wants more money. Should I spend the $75 on the RCA's, or tell him he's full of it and that the problem is with a shoddy installation?

pauldee · 08-08-2007, 04:18 AM

How about you tell him to put the cables in, and if they solve the problem you'll buy them. If not, he can keep his stinkin' cables. That is, if you are willing to shell out the $75 to get rid of the whine. If that's what solves the problem, what other option do you have?

rick3000 · 08-08-2007, 08:22 AM

Do you get the whine while using an iPod (or other) through a powered dock connector?
The whine is from a ground loop, I hooked up my iPod with a powered plug and I get the whine aswell, if you are just using the CD player or an unpowered input the whine should disappear. It is impossible to remove the whine completely but you can buy a $12 ground loop connector at Walmart that will make the whine almost unnoticeable.
Hope this helps!

Perfectlap · 08-08-2007, 08:58 AM

good question when are you getting the alternator whine? When the stereo is playing direct from the headunit or when you try to plug in something through via aux jack?
I tried to hard wire my Sirius satellite and got unebearable whine. Had to go back to the awful looking cigarette lighter. I would also get the whine with my MP3 player. Let us know if the RCA cables work when you are using the aux devices.

Wonko The Sane · 08-08-2007, 09:21 AM

I had this issue, myself, and the problem was the grounding as everyone else said... Although, I didn't buy anything extra to fix it.

I literally just pulled the deck out, started the car and played it while adding an additional chassis ground from the deck, I went and touched the chassis ground to a couple of different places/wires inside of the dash until I found one that gave me a solid connection, and my problem went away.

The issue is the noise sensitivity in the high-level to low-level adapter required to work with the stock amp. You're essentially taking your high-level signal from the speaker-out of the deck and running it through a filter to make it a low-level signal for the stock amp. ANY noise that happens in here will be amplified.

I know that this fixed it as shortly after that, I hit a bump and that wire came loose, and there was the unbearable whine again.

RCAs will not fix this.

Cheers!
~Aaron

Edit: I should clarify: The above is for an issue with an aftermarket stereo and the stock amp....

I had this issue with whine through my aftermarket amp later on, and it turned out that it was the noise isolation circuits in that MTX amp. I guess they really didn't plan on it being used for full-range, as it had no problem with it when the EQ was filtering out high range. I switched to a slightly higher quality Kicker amp and the problem went away. I did try to switch RCA cables first, as well as re-route the signal and speaker wires, but to no avail, swapping the amp was my only option there.

CJ_Boxster · 08-08-2007, 11:21 AM

I use to buy these devises called silencers and they stop all the alternator whining, they cost like 15 bucks. and you just place them inline with the radio power source.

Dr. Kill · 08-08-2007, 12:07 PM

These are all very helpful and probably accurate responses, but bottom line, you paid $1k for installation. Those bastards should troubleshoot and correct this problem for you.

pauldee · 08-08-2007, 01:25 PM

Oh, yeah, Doc. Doh! We didn't see the forest for the trees. Thanks for the yank back to reality.

porsche986spyder · 08-08-2007, 01:37 PM

Definitely a grounding problem. They need to find a better grounding spot on your car to fix that noise. It is a simple fix.

Wonko The Sane · 08-08-2007, 07:05 PM

Hahaha.. . Pauldee and especially Doc is right... We really over-diagnosed this one.. the real answer is exactly what Doc said.. You paid $1000 for this, and it whines, take it back to them and hope they can figure out how to ground it properly.

Either way, don't buy their RCA cables, they will do you no good. It's a ground.