Under Drive pullies issue?

Twista · Feb 14, 2012

Hello, i have a 95 GT with under drive pullies. I replaced the alternator last year and couldn't get the UD pulley off so i just used the stock pulley. So right now it has the normal UD pullies installed without the ALT.

On Saturday i was burping the coolant system with the heat on full A/C blast with the car idiling for 30+ minutes to finsh the burping process. At the end of this process i turned the car off and tried to restart it and it was DEAD. The battery was drained. So im wondering would having all the other pullies installed minus the ALT UD pulley cause this problem still.

I have a video of my dummy volt gauge. As you can see in the video when the A/C on the volts drop. Then you can see when i hit the gas and the rpm raise.. so does the VOLT.

http://www.youtube.com/watch?v=nO9GwZyJ1T0

Lightning Struck · Feb 14, 2012

rpm's will make the volt meter jump, all my cars have done that. Of course ive had pulleys on everyone of them too, so............??? I dont see having the stock pulley on it causing it to drain the battery though. Maybe just the end of battery life and bad luck that it happend on the pulley issue?

Twista · Feb 14, 2012

The battery is good. The alternator is pretty much new . The only thing that would mess with the voltages at idle would be the pullies correct?
Im not sure what comes with the UD KIT but im guessing... CRANK, WaterPump, ALT and water pump?

I have stock pullies i brought last year, but before i spend money on getting someone to swap them i just want to make sure having 3 of 4 UD pullies installed would cause this still. I was thinking with the Stock ALT pulley installed i wouldn't have this issue, but im now im guessing i will since maybe the other accessories are rotating slower?

Lightning Struck · Feb 14, 2012

Twista said:
The battery is good. The alternator is pretty much new . The only thing that would mess with the voltages at idle would be the pullies correct?
Im not sure what comes with the UD KIT but im guessing... CRANK, WaterPump, ALT and water pump?

yea the pulleys are 3 piece sets. I remember on my 91GT I had with the pulleys, the damn thing would heat up at long stops because of the slower than factory water pump ( due to the pulley) and also the lights would dim and the volt meter would drop at red lights. It drove me crazy, I was going to do the swap for the 94/95 alt but never did before I sold it. I was told that would fix the issue.

Musturd · Feb 14, 2012

Thts weird that shouldn't have happend man

GT Rob · Feb 14, 2012

I did my pullies but I didnt do my alt pullie I dont have any problems with charging

ttocs · Feb 15, 2012

people do not understand that the alt that was put in there was designed to spin at a certain speed. Slowing it down not only reduces its output but also limits its ability to cool itself. Smell your alt and I bet it smells smoked as sitting there with very little air over it for that time probably cooked it.

The other problem is that undercharging your battery, basically anything below 13v can cause damage over time.

I had pullies and hated having to worry about the voltage at lights, the alt and battery I had to replace later so I sold my pullies and put the stock pullies back on. I have never seen anything that justifies their use honestly as once you do some real upgrades like heards/cam you will want to ensure the water pump is moving at full speed.