Blazer eats alternators like popcorn

[Fireplug]

Guys you all have some good advice. The first question I would ask is do you have a aftermarket radio system in it?? Is it a kick arse system(pulling a lot of amps)?? Any other aftermarket stuff that eats a lot of amps??
Sec. its not the voltage out put but the high amp load that eats alternators. Do you have the correct amp size alt for that truck??
A weak battery will cause a alt to put out low volts and high amps untill the bat is charged.
Next please make sure that ALL THE BRACKETS AND BARS on installed. If any are missing that will cause the alt to shift and put way to much load on the bearings.
Just a few things to think about