Ok guys. I've noticed in my car that when my voltage drops to the red zone, right before it, my idle drops to about 500. When I'm in park, the idle is about 1000. Is there any way to raise the idle when I'm in gear? I feel like that'* what'* causing my voltage to drop to where it shouldn't be. It mainly drops when I hit the brakes. If I put her in neutral, it goes back to normal. If I rev it in drive, it goes back to normal as well. I'm really worried. I feel if I raise the idle, everything will be fine. I don't want to put my subs in without fixing the problem first.

The idle is changed in the PCM. But I don't believe that is your problem. I would guess your idle drops because your voltage drops first. I would be checking the cable between the alt and the battery, and the battery to ground. You also may want to check the alt. I think this mod will work on your car. Look at the alt plug, if you have 2 wires yes, if 3 wires, no. https://www.gmforum.com/showthread.p...ght=sense+wire

I can't really tell which drops first. I just don't understand why is drops when I brake, and raises after I let off of the brakes. The alt was just replaced not too long ago. I was hoping that neutralized the problem, but it didn't . I saw that before. I think Billboost sent me that link. I would like to do that, but I'm not too mechanically inclined. And I don't know if I know anyone that could help me with it. I just wish she would stop. Lol. I've been trying to figure out if a few different products would work. Hopefully you can help Dan

This one is for a Grand Prix, but then again, there'* no Bonneville section on there.

http://www.zzperformance.com/grand_p...=517&catid=107

And
http://www.zzperformance.com/grand_p...ts1.php?id=178

Would it be bad if I added both? I need to fix this problem ASAP.

No on the first link, not sure on the second link. Basically it'* a new battery to alt cable. The pre 2000 Bonnevilles don't have the alt sense wire and the voltage runs a little lower. That mod adds about half a volt or so. The idle drops because the voltage drops. Weak spark. The sense wire mod is easy if you follow the write up. Your simply cutting off the old plug and soldering in a new plug with 3 wires. Then connect one wire by the fuse box. Done. It makes the alt work just like a 2000+

Damn :(. lol. You say weak spark. Is there a way to fix that? I saw. I can't solder for the life of me. Lol. I might see if my mechanic can do it. Maybe he will? Lol. I'm not too good doing things like that on my own. Wanna come out to NY to help me with my car? LOL. I'm joking.

Fix weak spark with that mod. have someone help you if you must. It'* less then a half hour to do and I think that plug is like less then $10 on rockauto.

I'll see if I can find one of my friends to help me. A bunch of my friends are now certified mechanics which is a plus. lol

Cut and solder, that'* about it.

RPM drops, which slows the alternator and the voltage dropping is more common the cars.

This is because at 500-600 the pcm turns off the field of power to keep the alternator producing.

The best way to bump idle is through the pcm. However there is a set screw on the side of your TB that could be used to do this as well.

The problem being related to brake application leads me to believe there may be a vacuum issue also. Double check all connections and hoses.