While stopped at a light, stop sign or waiting in traffic my volt gauge in the dash drops down 3 or 4 marks below the 13 mark. If I put the emergency brake on with the car in drive and take my foot off the brake the volt gauge starts going up towards 13 again. While driving the gauge goes up above 13 and with the engine off and the key in the run position is is also above 13. I have only seen this with the lights on at night not sure if it happens during the day. I have replaced the alterenator and the battery checks out fine. The car starts up every time with no problems. All bulbs are work car is stock with the exception of aftermarket head unit (problem existed with and without the headunit in place). Any ideas?
Thanks Ray

 

Every car I have ever owned has done this. Sometimes it got a little better after I tightened the Alternator Belt. Maybe your belt is slipping. Since these automaticly adjust themselves, it might be time to swap yours out.

 

New Belt on a V-belt system and when I changed the alterenator out last night I made sure it was tight. What I am hearing is this normal for these cars they do not have a big enough alterenator at idle.
Thanks

 

Mine does this too, same as every thirdgen I have been in. Also only does this at night, with the lights on. There is just a whole lot more current being drawn, putting more stress on the alternator. I'm thinking the alternator is not spining fast enough at idle in Drive.

Anyways I think its normal.

 

Sounds pretty normal, but dont rely on that stock gauge. Get someone to idle your car in gear, and take a voltmeter to the battery. What does it read?

 

My car has been doing this ever since I have owned it. Seems normal, maybe check your timing and make sure it is set properly.

 

Perfectly normal operation. At idle with accessories running alt. output is low especially if it is a 105 amp unit. At this idle speed current load exceeds the alternator capability to charge. You could try a smaller pulley but it is not really a problem. As long as your battery is in good condition you will be OK. If you do a lot of night driving or short trips I recommend to everybody to do a trickle charge every other month. I use a cheap cigarette type and it really keeps the battery in a state of charge.

 

ITS NORMAL I HAD THE SAME PROBLEM AND I ALSO MEASURED WITh A VOLTMETER AT THE BATTERY AND OF MY GAUGE IT SAID 2 a 3 needles BELOW THE 13 BUT ON THE BATTERY IT WAS 14.1Volts so ITS GOOD !!!!


Greetz Marc from HOLLAND

e-mail: captain.software@wanadoo.nl

 

i have that same thing with mine.... is there an echo?... anyway.. i just put the car in Neutral and i put my foot on the brake.... it jumps back up to 13.... it just revs higher in neutral hope this helps aight peace

 

I currently own an 88 T/A GTA, an 89 Firebird, and an 84 Firebird, and every one of them do this... it's annoying, but doesn't seem to be anything cheap and easy you can do about it...