Did Underdrive Pulleys Kill My Battery??!!?!?!?

So I was driving up to visit my friends in Irvine about an hour and a half away and my car starts acting weird. I get a check gauges light and my speedometer is acting jumpy. My voltage, which was already lower after I put on my underdrive pulleys crawled to nothing. So I pulled over to the side of the road and had to be towed home. Waiting in my car for an hour. Just got back. What do you think happened? :confused:

Maybe your alternator/battery were weak to begin with. I had an underdrive pulley on my LT1, and my lights would dim a little at stoplights, but other than that I had no problems.

Well my dad thinks my alternator is too slow and it doesn't get the 12 volts that it needs all the time, could I get a new alternator with more output? or do I have to put my old pulleys back on? I'm certain it was my alternator now.

With the car running, put a volt meter on the battery, you should have around 14 volts, if the alt is charging correctly.

Buying a higher amp alt. might help,but yes the pullies are probably what caused this to happen.

Hopefully this didnt kill your battery completely and you wont have to get a new one. If its dead put a charger on it at low a amp rating,if that doesnt work the battery's cooked.

Good luck!

My guess the underdrive pulleys are your problem. They are not worth the so called gains on a street driven car. :eek:

Ditch the pullies...

cant you run an underdrive pulley if you have an overdrive pulley for the alt? thought i read that before on here.

Then what do you gain, the most screwed up thing you can do to your car. :rolleyes:

:cry: $53 down the drain :cry:

I've had my underdrive pulley for 4 years and haven't had a problem with it yet

I've had my underdrive pulley for 4 years and haven't had a problem with it yet

And how many miles have driven tin those 4 yrs?? :rolleyes: four or five times down the track??

underdrive pulleys will shorten the life of your battery,,, unless you put a lot of highway miles,, for yours it sounds that it is not just the underdrive pully as you state you were on the highway and the battery still dies,, check the battery but I would guess your alternator may be already out or on the way out.

I've had underdrive pulleys on my car for 100,000 miles. No issues with the battery. :)

I had mine on for like 50 miles and immideitly noticed voltage drops...Returned them.

Thanks for the help everyone, I'm getting a new alterntor reguardless. Yet another lesson learned :) .

i'm with brent...

had pullies on 3 different cars, well over 50,000 combined miles...

did i see a voltage drop...yes

did i have problems...no

And how many miles have driven tin those 4 yrs?? :rolleyes: four or five times down the track??
:rolleyes:
Actually about 60,000 miles, and many many more then 4 times down the track.

If/when I get the pulleys I will end up getting the ALT pulley w/ it because it helps correct the ALT rpm to keep the voltage from dropping... -Am I right on that one?

EDIT: WHere'd you get pulleys for $53?!?! :eek:

If/when I get the pulleys I will end up getting the ALT pulley w/ it because it helps correct the ALT rpm to keep the voltage from dropping... -Am I right on that one?

EDIT: WHere'd you get pulleys for $53?!?! :eek:
I was told that if you are running something from your battery, like a stereo system, then you sould get the alternator pulley. If your not then it's not necessary (from what I was told) I guess every car is different, but so far no problems for me.