sound like a whiney noisey supercharger?
I have been hearing this noise for about a month and thought it was the supercharger whining. Just drove it tonight and noticed that at idle, the headlights get dim and dash warning lights come on...abs, trac, and more. Then when I get rpms up, everything gets normal and headlights get bright again. Anyone else ever "hear" their alternator whining?

 

Sounds like how my diodes went PITA replacement but not hard. GGet yours rebuilt after testing.

 

Sorry, I don't understand...??

 

Yes, it is a common symptom of alternator failure. Any parts store can diagnose it.

 

The alt has diodes in it and mine whined when they went. It is a pain in the a^# to replace. Get it tested on the car to be sure and it is much cheaper to have yours rebuilt then to buy a reman unit from a parts store.

 

Yes, the bearings inside are howling like crazy. A couple of years ago a guy was driving through my town in an XJ8 and his alternator locked down the engine (until we removed the belt) right in front of my shop.

The alternator started howling on my Vanden plas shortly after getting it. Dips in RPM were accompanied by dips in voltage and dimming headlights. Within 2 months or so the noise was so loud it was obviously out of the ordinary, I busted out the stethoscope and found that it was the alternator. After replacement, she is quiet as a mouse. Admit it though, it is fun acting like your car is an XJR

 

Yes the sound is very agressive, although it is a VDP Supercharged.

 

You can have a whirling noise from many items in the car - but the fact that the lights are doing what you say -----points to the alternator going.

Not hearing the noise it is hard to tell but normally failing bearing do not initially cause the alternators output to fall -- the sound of the electric's going is more of an odd oscillating sound. Depending on what is up will determine the rebuilding ability.


I will say that I once thought I had a bad alternator and it was actually a shorted battery coupled by a failing water pump -- but this is an unlikely occurrence. Normally water pumps when they first start to go quiet down when the car warm up .......and they start to leak.

How old is the battery? the constant discharge from a bad alternator will affect an aging battery

 

Donzi, did you ever get this issue sorted out, was it definitely the alternator making the high pitched noise? I just had a new serpentine belt and pulley installed last week, which it definitely needed, but I wish now I had done the alternator at the same time. I was thinking the whining sound was due to the fact that my aux heater pump wasn't working (a new on is on the way, it's COLD without it), but it's obviously not the pump. I'm wondering how long the alternator will continue to charge, even with the whining sound. It sounds exactly like this car does:

I don't have any charging/dimming issues yet, idiot lights, etc, but I'm guessing eventually the alternator will completely die, but I'll get warning lights or sluggish cranking as an indicator that it's on it's way out?

By the way, I noticed you're in Dayton as well, Cheers! (we are actually in Beavercreek)