Hey Guys. I got a 98 GT and recently the voltage gauge in the gauge cluster has been reading lower than regular. It usually sits between R and M in NORMAL. Now it has been between O and R. I tested the battery at idle ( approx 750rpms) and got 12.4 volts. Then tested the alternator at idle and got a solid 14.2 volts. I was wondering if it could be the voltage regulator on the alternator that could be causing this problem. Any input would be great. Thanks

 

Go up to auto zone and have them test the battery and bring an 8mm and 10mm wrench with you. If the battery is good pull the alternator off and have them test it.

 

so at the battery your getting 12.4 with it running and at the alternator positive post it was getting 14??? sounds like a problem between the alternator and battery. a bad battery could cause it too, but it probably wouldnt start.