how do the volts look when the car is running? are they high? How about when you turn the lights on, do they go way down?
Maybe the car hasd pullies on it, which would make a stock '88 alternator not charge very well... If so, get the 130 amp and install that! I have an '88 GT and had the same problem... after going through 3 batteries, I finally upgraded the alternator, and no more problems after 3 years! good luck!
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Joe!
1988 GT, 167,000 miles!!! 13.71@105mph Check out my listing!
Click here! Or my website:
www.joe4speed.com
1999 Ninja ZX-6R 10.32@135mph!
1993 Olds Eighty Eight LSS