When I start the car the warning light stays on and I do a quick scan of my instrument panel and the battery isn't being charged. As soon as I rev the engine once, the light goes out, the voltage goes up to where it should be and stays that way until I shut it off. Does this sound like an alternator going south, belt slippage or something someone has seen and dealt with before? This has been ongoing for some time. Just bought a new battery 'cause the old one cooincidintally dropped dead. Also just noticed a slight whistle from the front of the motor soon after start up but goes away quickly. Seems that after I fix one gremlin, another pops up.

 

Sounds like something is leaking /dripping onto the belt or a pulley when the engine is off, blip of the throttle clears it off.

 

I believe you can often hear when one of the accessory belts slip -- they screech. Check tension and check for fluid on the these belts in case Jamesr6967 is on to something. It's the easiest thing to do now, and free.

I'm guessing next step is voltmeter.

 

If like the 928 then there is a resistor on the rear of the cluster guage that is bad. It is not providing enough power to 'excite' and start charging. The charging system runs in series with the warning light also. If it is out then no charge. Pull the cluster and check the resistor for good contact/corrosion.

 

Since you can verify that the alternator isn't be excited by using a voltmeter (same on the one in the car) and the red warning light comes on as it should it's very possible that the resistor might be the culprit. I'll get at all the grounds and the resistor soon since I'm replacing the dash with a virgin one I found at a swap meet. As far as fluids or oil leaks on the belts: they wouldn't dare. I replaced virtually every rubber and mylar seal in the engine and it's as tight as a tick. Also replaced and tensioned all the belts. I do appreciate all the opinions however.

 

Took the car out on a local road trip and the voltmeter in the dash started jumping from around 12v to around 13v (where I usually see battery charging). No red warning light. I don't know what to make of that. This is a new indication. I was worried that the alternator was failing and I'd end up on battery power only. Good thing it's a new one. I ran over a couple of sharp pot holes that jarred the car but it didn't change the indication so I don't think we're talking a bad connection issue. Revving the engine didn't change anything either. Ran solid on the way home.

 

Voltage regulator might be worth replacing as not too many $$.

 

There is a blue wire that should be connected to the alternator. That is the wire that excites the alternator. It may be loose. I disconnected mine on the race car, just rev the motor once and it will start charging every time.

 

I'll check that wire out. Where is the voltage regulator on the NA car?

 

On the back side of the alternator. Usually white, held in by a couple small bolts. Should only be about 12-15 bucks. I would suggest buying the more expensive version however as I lost the regulator and blew up a battery last year at the Glen.

 

Paragon sells an aftermarket for about $18
http://www.paragon-products.com/Volt...p1.109.220.htm

The VR should be changed if the carbon contacts-"feet" are less than 1/4"-5/16".

To do the job correctly, the VR alternator slip ring should be machined flat. If you do not machine flat or at least get rid of the old worn areas the carbon contacts ride on you will chew up the new VR carbon contacts.

https://rennlist.com/forums/928-foru...procedure.html

John