dumb electrical question about my truck

[monzamess]

Ok, so I'm out driving my S-10 for the first time in two weeks, and I notice that if I really floor it, at its peak, the voltage drops and the lights dim. Only for a split second--otherwise it's fine. Any guesses as to what's up? My first guess is the belt is slipping on the alternator but the battery should keep the voltage to at least 11-12 volts right?

[OldsStarfire]

Bad Voltage Regulator? Could possibly be the belt. What year S-10?

[zeke]

Sounds like loose belt

[cjbiagi]

Even if the battery keeps it at 12 volts you will still see that drop in volatage & lights dim if the belt slip. You would probably go from 13.5 - 14.5 down to 12, so you could see some effect from it.

[gerbsinmd]

Dennis,

Make sure that your belt tensioner is still working. It could be stuck or bottomed out which could mean the belt is stretched.

Darrel

[monzamess]

Ok, thanks everyone for the suggestions. In fact the alternator, belt, and belt tensioner are "relatively" new on the truck. They were fine but since they're cheapo replacements maybe one or more of them have reached the end of their lifespan.