My 2001 chevy silverado truck has a problem with the alternators going out. I am on my forth alternator. The dealer can not find any problems and keeps replacing the alternator. The last one only lasted three weeks. I checked the voltage on the new one when I got home and the voltage is at 14.7 volts. I think what is happening is for some reason the alternator will start over charging and burns out. I will check this out this weekend and see if the voltage output spikes. I have 260.000 miles on my truck. Has anyone else had this problem or any ideals on what I should check ?

 

Rule of thumb, check all grounds, check battery condition, (load test with voltage @ 12V minimum). KOER check output with DVM or diagnosic reader. 4 alternators to date dosen't sound like coincidence. Something is absorbing the voltage or causing the alternator to full field.

 

All I can tell you is to check every single connection that relates to the battery,and the alternator. Every now and then you will run across a brand new alternator that has a flaw in it,but you won't run into 4 of them that are bad. How old is the battery?

 

Thanks for the info. I will do some checking of the system this weekend. Checked battery and it is good.

 

i have the same prob with my 2001 right now, im on alternator # 6 in the last 7 months.. what mine does it will cut out at around 2500 rpm then cut back in once it goes over or drops back down.. im going to try a duel battery setup with a isolator and run new ground straps .. all i know is its getting old and the guy at my auto parts store is getting tired of seeing me come in with a alternator all the time,, lol..

 

there r two alternators for that truck. One is 105amp and the other is a 130amp.