While driving my car yesterday I noticed that on the highway while travelling about 3500rpms (c4 with 3.73) my battery light comes on and the volt gauge shows around 18volts. If I let off the light goes off rather quickly and volts bump down to between 14 to 16. I am pretty sure this just started. The combo only has around 200miles on it. I am running only the crank,wp, and alternator. Do I need a different(larger)alt pulley? Or is it a problem with the voltage regulator. Thxs