I had to change out an alternator this summer because it was putting out too much voltage. My amp kept cutting out and I thought it was the amp, but then I glanced down at my scangauge one day when the amp cut out and the voltage display read 16+Volts! I ordered the Maniac Motors high output alt, and while I waited for delivery, I was still driving the car, usually it was in the correct range, but once or twice a day it would spike up and the amp would always cut out when it spiked so I knew to look at the scangauge...one day it was reading almost 19V! Luckily I didn't blow anything or mess up the ecu, but it definitely pays to have a voltage gauge.
1997 MX-6 LS