Strange Electrical Problem on 2001 996TT

[msv]

Hello,

I'm looking for some insight on a strange problem I'm experiencing.

After about 10 minutes of running, the left front dash speaker begins to buzz and when this buzzing starts, it also picks up alternator whine. Up until this starts, there is no problem at all, and the stereo operates as normal. This occurs whether the stereo is on or off. If when this begins I turn the headlights on the buzzing and alternator whine will cease and everthing will again be as normal. After a similar amount of time, it will begin again, and I can once again eliminate it by turning the lights on and off.

I have a fair amount of experience with aftermarket stereos, and have dealt with alternator whine before, but this is odd as it is not constantly present, and can be eliminated by using the light switch (my belief is that it is simply the change in electrical load that is making it cease, not directly related to the lights themselves).

Does anyone have any ideas they could share? Help is greatly appreciated!

Thank you.

Mark

[zebswiss]

Hello,

I'm looking for some insight on a strange problem I'm experiencing.

After about 10 minutes of running, the left front dash speaker begins to buzz and when this buzzing starts, it also picks up alternator whine. Up until this starts, there is no problem at all, and the stereo operates as normal. This occurs whether the stereo is on or off. If when this begins I turn the headlights on the buzzing and alternator whine will cease and everthing will again be as normal. After a similar amount of time, it will begin again, and I can once again eliminate it by turning the lights on and off.

I have a fair amount of experience with aftermarket stereos, and have dealt with alternator whine before, but this is odd as it is not constantly present, and can be eliminated by using the light switch (my belief is that it is simply the change in electrical load that is making it cease, not directly related to the lights themselves).

Does anyone have any ideas they could share? Help is greatly appreciated!

Thank you.

Mark

Mark,

1. My first thought is a possible build up of static electricity... It may sound weird but the time delay makes sense as well as the electrical load temporarily fixing the problem.

If this is the case you should check grounds and crossed wires, maybe even double ground the speakers with a separate wire.

2. I also remember my Dad saying that older cars were always getting interference on the radio from the spark plug wire, the problem was remedied by a small cylindrical "suppressor" on the external coil housing... I know your car is much newer but it may not hurt to open the engine bay at night (as dark as possible) and look for electrical displays that might be causing a small short.

3. Since your speakers buzz with the radio off... there almost has to be a short somewhere... they are getting enough power from somewhere to buzz (maybe your alternator has a bad spot?)

Best of luck, zebswiss

[msv]

As soon as I get the time I'm going to pull that speaker out of the dash and see if anything seems amiss. That's where I'll start and work from there!

[Newfarm]

I'm sorry for bringing such an old thread back up from the dead, but I'm having a very similiar issue with my new-to-me '02 C4S. It comes and goes, not on the 10 minute timer that the original poster here described, but apart from that it's pretty much the same.

The whine follows the RPM if the car is running, but it's still there if the engine is shut off.

Anyone have any sort of idea where I could even begin to troubleshoot this one ? I was thinking maybe some little-used fan in the HVAC or something like that (mostly because I belive there are some of these fans around and behind the looms that has the wires to the speaker(s)).