One wire alt. operation

[lovemybadkitty]

Thanks for all the info. Ok For one the alt. is a brand new GM replacement and since I have the same problem it's not the alt. or internal reg. Once my computer would not send the ground signal to the start relay after the security check so I had to make a jumper to ground to get the car started. Then at one time the horn should blow twice when the alarm is set but would only blow once. That problem cured itself. Maybe bad computer? Bad connection on computer?

[twistedtech]

The PCM is not the issue here at all.All in this thread are right and yet somehow all are wrong,go figure.In a basic term,the more the system draws,the more the alt will produce,if it is able to only produse 25 amps,that's all your gettin.Being a 98 it is prob a large output alt in a small case alt,bad plan on GM.

[99firebird]

I'd check all grounding straps and cables before changing the computer out. I've heard of more weird problems than I can count from bad ground.