By Majestic Moose - Mon Sep 27, 2021 7:25 pm
- Mon Sep 27, 2021 7:25 pm
#106677
My car keeps killing alternators. It is easy to blame the alternator if one or two fail but with a third it might be something else.
First a little history. When I bought the car the PO had replaced the alternator and it never performed well, it turned out to be a 75A unit from an 80's Audi with no back cover or cooling hose mounted. Actually this one never failed but it does not provide enough output.
I bought and installed a used correct alternator, it worked okay but it was noisy so I knew it would not last long. It also need a rev around 2500 RPM to kick in.
I replaced it with a Bosch 325x and fitted the back cover and cooling hose. It worked great.. for one day, about 50 miles.
The used unit went back on. It finally failed while driving. On removal I saw it was the diodes destroyed.
I installed another Bosch 325x, this one worked great for exactly two months and failed on my way back from Frenzy. This time I noticed the volt meter at 11v after a redline run in second gear. I was thinking maybe I over revved the alternator but my pulleys appear to be the correct sizes.
Everything on my car has been gone through. I have no current draws; I can park the car in November with the battery connected and no charger and it will start right up in Spring.
All bulbs are LEDs but I do have an electric radiator fan setup that only runs when needed. It pulls 17A.
The battery is a beast of a Bosch AGM. It is from 2016 but holds its charge and I was able to drive 60 miles with AC and lights on and it was still at 12.3v when I got home.
So I am at the end of my patience and willing to consider other options. I can replace this one for free under warranty but I am starting to think there might be something causing these alternators to burn up. For now I cannot figure it out, any ideas?
First a little history. When I bought the car the PO had replaced the alternator and it never performed well, it turned out to be a 75A unit from an 80's Audi with no back cover or cooling hose mounted. Actually this one never failed but it does not provide enough output.
I bought and installed a used correct alternator, it worked okay but it was noisy so I knew it would not last long. It also need a rev around 2500 RPM to kick in.
I replaced it with a Bosch 325x and fitted the back cover and cooling hose. It worked great.. for one day, about 50 miles.
The used unit went back on. It finally failed while driving. On removal I saw it was the diodes destroyed.
I installed another Bosch 325x, this one worked great for exactly two months and failed on my way back from Frenzy. This time I noticed the volt meter at 11v after a redline run in second gear. I was thinking maybe I over revved the alternator but my pulleys appear to be the correct sizes.
Everything on my car has been gone through. I have no current draws; I can park the car in November with the battery connected and no charger and it will start right up in Spring.
All bulbs are LEDs but I do have an electric radiator fan setup that only runs when needed. It pulls 17A.
The battery is a beast of a Bosch AGM. It is from 2016 but holds its charge and I was able to drive 60 miles with AC and lights on and it was still at 12.3v when I got home.
So I am at the end of my patience and willing to consider other options. I can replace this one for free under warranty but I am starting to think there might be something causing these alternators to burn up. For now I cannot figure it out, any ideas?
Last edited by Majestic Moose on Mon Sep 27, 2021 8:42 pm, edited 1 time in total.
Alex.
1983 Black 5 speed 928S
1989 Dove Blue 5 speed 928S4
1983 Black 5 speed 928S
1989 Dove Blue 5 speed 928S4