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My 1999 Pontiac Grand Am Won’t Start

I’m having a problem with the charging system on my 1999 Pontiac Grand Am. New alternator. Fuses good fusible link good just won’t charge.

ProTech:
Have you done a charging system test?

Yes did a load test on the battery that’s good alternator tested good off the car while car is running only at about 12 volts and eventually drops until car dies.

Since the battery and alternator test ok…you have only have a couple possibilities left, the PCM is not turning the alternator ‘on’ to charge the system like it should, or you have a wiring problem somewhere.

Well wiring would have to be between the PCM and alternator i have power from the starter up through the fusible link to the alternator and I also have power at the orange wire coming from the fuse box fuses are good and so is the fusible link there are 2 other wires on the connector don’t remember the color off hand one is grey they are the l and f terminals coming from the pcm what kind of power should they have.

You did happen to check the GEN fuse right?!? Make sure it is not blown.

Yes there are 2 fuses in the charging system i believe if i remember the diagram right one in the car and one under the hood along with the fusible link going to the starter all of them are fine.

The F terminal gray wire you should have 12 volts on from the PCM. If you do not, the PCM is bad, or the wire is broken between the alternator connector and PCM connector.

Alright. Well I’ll check that at the PCM tomorrow the alternator and see what i got.

Isn’t the F terminal the input from the alternator to the pcm and the L terminal is the output.

The F terminal is field duty cycle signal. That’s the gray wire…..the red wire is regulated voltage signal and the orange wire is fused power. You should only have 3 wires on that connector.

Yes. The orange from the fuse the grey wire and one other wire not sure on the color then the large red wire going to the starter.

Yes, correct. And I’m talking the connector itself….NOT including the thick red wire on the back of the alternator. I’m sure you’ll find your problem lies in that gray wire, or the PCM.

Thank you for your help.


Battery and Starter

I took the battery out of my 1997 Pontiac Grand Am with the quad 4 . It has been unhooked while waiting for the starter to be rebuilt . I got tired of waiting and bought a new starter . I finally put the new starter in and now it won’t do anything when I try to start it . Do I need to do a master reset to get it to start ?

There is no ‘master reset’ that you can do. You either have one of two problems. Either the battery you put in the car is no good and won’t crank the vehicle, or you have a faulty new starter. Some wiring checks would need to made, etc, such as checking for power at the starter when you crank the car. You might want to try to jump the vehicle first since that’s the easiest and you can tell if you have a bad battery right away.


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1 comment to My 1999 Pontiac Grand Am Won’t Start

  • Genis

    use the test light disconect the neg batt tmaienrl conect the test light between the tmaienrl and post the light will go on now touch the tmaienrl to the post tle light should go off now pull the eminal away if the light goes back on you have a problem start un pluging things start with the alternator than fuses when the light goes off put the other fuses back in to make sure now you know the circut Was this answer helpful?

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