Join Date: Mar 1999
Location: College Park, MD USA
I'm having a little trouble with the electrical system on my 86 IROC (VIN H). Normally, the voltmeter on my instrument display reads between 12 and 14 volts, which is normal for that car. Lately, though, the meter has been falling to around 10 or 11 volts.
At first I thought it may be a bad battery connection, since I had a problem with that about a week ago, so I cleaned and tightened the battery terminals. It seemed to return to about 13-14 volts when I drove it, but later in the day it started falling off again to about 10-11.
Occasionally while it is low it'll return to normal (about 13) when I'm driving, but then fall back off gradually. I haven't noticed any dimming headlights or power loss, but I want to get this before it leaves me stranded somewhere.
My guess is alternator or voltage regulator, but the voltage regulator is built into the alternator, so I'm thinking of replacing the entire alternator, not a big deal, but I wanted to make sure I haven't missed anything before I buy it. The belt for the alt is tight enough, I have a new belt I've been waiting to put on for a while, anyway.
Does my thinking sound correct? Sorry to waste time with something this small but I want to know if there's anything else that could be causing it.