911Jeff

I have upgraded the stereo in my '98 Boxster:
Nakamichi CD35z Head Unit
ADS P-100 AMP
ADS 300i Speakers
TARA LABS cables
The problem is a high pitched whine (Alt. noise??) that seems to vary if I move the cables from the head unit to the amp. (Notes: I have tried different head units and amps with the same problem. The cables from the head unit are TARALABS P-33 which are heavily shielded. The path is through the console area, to the hole in the firewall above the pedals, up past the battery along that back "second firewall, through that second firewall on the passengerside to the amp that is on the other side of that secondary firewall right behind the spare tire. I have tried various filters on the inputcables and on the 12 volt posistive and ground. All units are common grounded.) The factory unit didn't whine and the new units only whine through the power amp ( the dash speakers are wired directly to the onboard amp in the head unit and are fine). The whine also causes the amp to overheat on warm days and shut down. I am fairly knowledgeable about 12volt stereo systems and have done this same type of system in my 86 911 and my 96 911 without any problems.
The Boxster problem has me stumped!!!
Any insights or thoughts might help.

Turboflyer

Well until you said that the unit overheats when whinning I was going to suggest a capacitor on the altanator. Not sure now. wouldnt be that much trouble to try it. If its overheating something else is not right.

911Jeff

I thought that the Boxster had a capacitor already installed on the altanator. I have never looked (or even seen the engine). Is it easy to check?

Turboflyer

Actually I dont know if there is one or not. I had the same problem without the overheat on my experimental airplane. The capacitor did the trick. Nothing is easy to check on the boxster unless it lights up on the panel