Toejam

My alternator doesn't want to charge very well when I first start my car up. The voltmeter reads low (in the orange) even when I start driving the car, and will not leave the orange until the car warms up a little and I start driving it hard... this is the key really.. if I really get on it, the gauge will jump up into the correct position and stay there... even when I go back to idle. I know this is not simply a problem with the gauge because when I turn my headlights on they are dim until I do the above. The other night, my puny headlights were even more dim for about 45 minutes of driving before the alternator would wake up(thankfully it was before the deer-laden two lane road). This was the longest period I've experienced when the alternator would not wake up as I can usually get it working within 10 minutes.

Does this sound like a bad ground maybe? I dont know exactly where the ground straps are so maybe that's an indication that they need cleaning? Also, I'm not positive but it seems like the cold weather may have contributed to the problem as well.

Any info would be great! TIA!

Jon F

I had the same problem (though not as severe) and cleaning the contacts on my alternator solved it. If you are still having problems, you may need to pull the instrument pod and clean the resistor and low-voltage bulb socket contacts, and perhaps replace the printed circuit.

SilverSFR

Toejam,

Take your 928 to say napa/pepboys and have them test your ALt/Batt. This will tell you weather or not they are the problem.. Best of all, they will test them for free.

SilverSFR

Robert_H

Exciter thread

It sounds like it might be this (see attached thread regarding the exciter circuit/coil) that might be causing the problem.

With my car, after I start it, the gauge registers very low until I blip the throttle and then everything get's much brighter (lights, etc.) and then the gauge jumps up much higher.

Rob

Drewster67

http://autoexpress.safeshopper.com/index.htm?75

If your alternator is going bad - check out the link.

Toejam

I haven't noticed it happening lately... tightened the belt a little and haven't seen the problem since... crossing fingers for now.

Marc Schwager

Replacing the circuit board on the pod fixed my LV reading. I never noticed the dim headlights that you mention though. Check the voltage at the jump points, and if you haven't done it clean the grounds. Wally's electrical PM checklist can work wonders.

Toejam

Drew did you get an alternator from Autoexpress? It seems like they have good prices(with 3 yr warranty).

I ask this because my alternator is acting up again. Lately it was actually reading BETTER than it normally does (around 13 volts--straight up, which is much closer to the reading at the terminal under the hood.. 13.8 or so with no lights on) but then it started to "dance". It sometimes bounces quickly between 12 and 14 volts and everywhere in between when driving now. It will actually make my headlights flicker slightly too, as well as my console/instrument lights.

I do need to pull the instrument pod again soon and clean things up/replace some bulbs, etc etc, but that circuit on the back shouldn't actually interfere with the charging system or other aspects of the main electrical system, correct? The only benefit from cleaning that would be to correct a needle that wasn't reading properly, and I'm certain my voltmeter is reading properly (because the lights on the car correspond to the action of the voltmeter).

And that positive post on the passenger side under the hood is an OK spot to check voltage, correct? I'm going to go see if I can get my voltmeter to start jumping again and take another reading.