sapp91stang

INSTALLED UNDERDRIVE PULLEYS ON 91 5.0 NOW ITS ONLY CHARGING ABOUT 12 VOLTS AND WITH LIGHT AND HEATER FAN ON IST ABOUT 11 VOLTS AND STALLS I TURNED UP IDLE A LITTLE TO ABOUT 900 RPM IN NEUTRAL BUT THE VOLTS DIDNT PICK UP HAS ANYONE HAD THIS PROBLEM? ( INSTALLED NEW ALTERNATOR ABOUT A YEAR AGO )

PRO50SC

Ok first turn off the caps. Next, welcome to underdrive pullies. Next mod for you, is upgrading to the 3g 130 amp alternator. Problem solved.

billyboy1955

I was gonna install them in my 90 GT. But after reading about the negatives I decided against it.

1990mustanglx

samt hings happening to me. When you turn your radio on does the volt meter go almost all the way down? and wen i turn my headlights on it goes way down too. i got a system in my car though and wen my subs hit the volt meter goes down then comes back up and most of the time its only at like 10 volts.

ricepatrol

LOL

Or you can just use the stock alternator pulley, and then put the underdrive on the new alty

[sm=closed.gif]

sapp91stang

the cd player turns off when u turn the fan on

ricepatrol

Yeah guys, I would never run it that low. Put the stocker back on if you still have it. I would hate to come out to a car with a dead battery, or have it stall, or the light be too dim, but that's my opinion.

dsum14

Don't use the underdrive pulley on the alternator. I installed only the water pump and crank pulleys and haven't had any problems.
D

marx91

you have to watch mixing under drives with stockers sometimes the belt wont fit right

sapp91stang

both alt pulleys are same size