Hey all,
I got a 2001 Blazer and I have problems with the alternator it seems like. I put in a ACDelco 335-1086 two months ago and it worked perfectly giving me a little over 14 volts according to the voltmeter. This morning I noticed that the car barely turned over but started. Later in the afternoon it started and turned over fine but the voltmeter has dropped to somewhere around 11-12 volts and the lights have gone dimmer. When I rev the engine it goes up to 14 volts but drops back after a while. Should I change it out? What brand would you guys recommend.

By the way the car has 144k miles and this happened after a 4 thousand mile road trip.

 

we just had a hyundai sonata in the shop doing the same thing, the alternator charged at lke 12.5 sometimes if you reved it up it would go up. we replaced the battery as it was old and weak then it started charging at 14.4 but after you throw all sorts of loads on the system, brighths, blower motor, a/c and everything else you can turn on it went back down to 12v again. so if the battery is good its just the alternator going out

 

Turned out it was the battery... This was after a one week roadtrip going for 4000 miles. I think things got too hot under the hood.