My daughter has a 98 Firebird 3.8 V6 with 43k miles and out of warranty. At 35k miles I had to replace the alternator with a remanufactured alternator in the spring of this year. Because I don’t drive it that often, I don’t know when the problem started, maybe in the last 3 or 4 months. When you first crank the car in the morning all the light will pulsate at a very noticeable fast rate for about 30 seconds. After the 30 seconds, the lights will pulsate at slow rate for about 2 minuets, than the lights will have a very slight pulse. I went to the auto parts store to check the alternator and battery. Both checked out OK, but I decided to replace the originally battery with a new one. This did not solve the problem. I replaced the alternator with a new remanufactured alternator. The new remanufactured alternator would not charge the battery or putout any voltage. Replaced the new remanufactured alternator with another new remanufactured alternator and it would not charge the battery or putout any voltage. Put the first remanufactured alternator, which I bought in the spring, back in the car and the alternator would charge the battery and putout voltage, but I still have the pulsating problem. I checked the control circuit voltage from the PCM to the alternator (the GM Service Manual calls the alternator a generator and the circuit should have a value of B+). I got a voltage of 4.5 to 5.0 volts at the end of the wire going into the alternator and at the pin at the PCM. The parts store checked their 2 remanufactured alternators, both of them check out OK and using their tester, the control circuit had 10 to 11 volts coming out of it. We checked the circuit in a 95 or 96 V6 Firebird and we got 9 to 10 volts.
Questions:
Has anyone had the pulsating problem and how did you solve the problem?
Has anyone ran into the problems with the remanufactured alternators and how did you solve that problem?
What I am worried about is when the alternator fails, what do I do about getting an alternator that works?
Jerry
Craftjl60@hotmail.com

 

Where are you getting your parts. I would reccommend getting a genuine ACdelco remanufactured alternator. If the unit you have now only puts out 4 or 5 volts while on the car it is not performing up to spec.

 

The first alternator, I get 4.5 to 5 volts on the wire coming from the PCM to the Gen.L Term. of the alternator and I get 12 to 15 volts output from the main wire of the alternate to the battery. The other 2 new remanufactured alterantor, I still got the 4.5 to 5 volts from the PCM to the Gen. L term. of the alternator, but I get 0 volts output from the main wire of the alternator to the battery.



[This message has been edited by jlc (edited December 22, 2000).]