SouthernRex

(1998 TransAm WS6 A4 ~70,000 miles)

I put a brand new alternator AND battery in the car today, and the same problem persists: Anytime it is slightly humid or moist out (especially if it just rained) my voltmeter acts psychotic. Under load, such as higher throttle, the voltmeter LOWERS instead of raises. It has actually killed the car this way (systems failing and then the car finally dying as the voltmeter plummets.) The new battery and alternator have made it that the car hasn't died so far, but it still dances near the yellow line everytime I touch the throttle, and I figure it is only a matter of time. Is it possible I got a bad alternator?

RPM WS6

iTrader: (3)

So everything looks/acts fine while it's idling or cruising, but if you accelerate it dips down, eventually getting into the "warning" area? And this only happens if it's damp or raining out?

In dry weather, none of this is an issue?

What if you sit at idle and increase load on the system (such as running multiple accessories and such), but without touching the throttle?

jetech

Checked the grounding cables?

Ls1Ryan2002

If you have access run a test to find out the output of the battery and the output of the alternator at idle, then under load. Should be able to tell right away, if not check the cables and make sure they are in good shape. Check for corrosion or damage. There is a chance that the alternator you received was faulty, running a load test on the alternator is likely your best bet considering its voltage drop under load.

SouthernRex

100% correct. I almost bought a new alternator "last time" this happened, (all of last year), but as fall came and the weather was dry and cool... it seemed to correct itself. Now the storms are coming (I live in Florida), and the car has died on me 3 times WHILE DRIVING.

My stereo and subwoofer (nothing serious, Bazookas that fit in the natural rear seat fitting and some other brand high-frequencies with an amp/receiver) lights/fog/high-beams, vent fans... all seem to have little effect on the voltage. But putting a load on it: (D) with 2500-6000 RPM, and the needle dances dangerously close in the yellow (and before the new parts, quickly became "CHECK GAUGES" etc.)

I should note that it isn't 100% consistent... I could be at 4200 RPM and it could be near yellow-line and suddenly shoot up to proper safe voltage for a few seconds, and then back down.

SouthernRex

For anyone that browses and finds a similar problem, it was the wire going in to the engine wireharness that was in terrible shape. Had to replace and crimp that, and everything came back to life.