My alternator is sleeping on the job. First noticed an issue today when my "check gauges" light came on and saw the voltmeter registering at about 8-9V. I restarted the vehicle and the gauge slowly climbed to just past 12V and held there. Measuring at the back of the alternator, I'm only showing 12.1V steady. The battery is showing 12V across the terminals (i'm in year two of an 8yr duralast gold, so I'm working with the assumption it is fine).

Do I have a dying alternator?

 

I would have the alternator and battery tested.

 

It sounds to me like a lousy alternator. I'd get it tested at AZ or Advance and also get the battery tested under load.

 

yup i agree that it sounds like a dying alternator, iirc they should be putting out about 14v with the engine running

 

14.4v, but close enough shrp LOL

 

ahh, i doubt the battery would notice less than 1/2 a volt of difference

 

wouldn't you know, a good night's rest and the alternator is now putting out 14V. If only it was that simple.

 

Yeah I know, very unlikely.

For future reference to whom it may concern, this is where the voltometer should read when all is working well:

 

+1 Sounds like a bad alternator.


As for the battery, I'm sure it's fine.

 

and this is what the dash looks like in the new gen trucks w/ everything running correctly (it was like 10 degrees out this day, just fyi as the idle is a little high in that pic, usually sits exactly on the 500rpm line)