GMC Sierra - Alternator

After replacing my battery I drove the truck around and got the "battery not recharging" warning again. Needless to say, my alternator needed to be replaced. I removed it following the videos below and took it to AutoZone for testing. It failed the tests and I decided to purchase a new alternator. Not cheap, but at least off the shelf with a warranty.

How to Replace An Alternator
This video was exceptionally helpful regarding more specifics as to my truck, a 2003 GMC Sierra 1500. However, it was a little "weak" on the what and why behind the serpentine belt. Also other relevant videos from AutoZone on whether or not to replace the alternator.

Replacing the Serpentine Belt
This video cleared up the questions about the serpentine belt.

Important note from this exercise is that AutoZone videos are great, but they often need to be supplemented with specific videos on the topic. Also, vehicle diagrams are generally awful. My manual is terrible. Even AutoZone has diagrams online that are basically worthless.


The battery location in the GMC is jammed in the corner. Difficult to reach. Also has a bar that seems pointless (see in the corner on the frame, moved in photo), and there is a bolt that is tough to reach. Great design GMC.


Battery removed, old alternator still installed.


New alternator and new battery. Required the mallet and hammer to get the alternator in. Luckily one of the videos warned about this possibility.


Check that the serpentine belt is on correctly. Huge pain.

You can see I removed parts in order to reach the tensioner for the serpentine belt.

At the conclusion the truck runs fine and there are no warnings.