2012 GMC Sierra 2500 HD Alternators

Genuine GM alternators for the 2012 GMC Sierra 2500 HD, at wholesale prices. Alternator output rating varies by electrical load, so a truck with a tow package or upfit wiring takes a different unit. GMT900 HD through 2014, K2XX HD from 2015 to 2019, and the T1XX HD from 2020.

When to replace

A battery light, dimming headlights at idle, or a no-start after a short drive. On a heavy duty pickup, single or dual rear wheels, gas or diesel, and cab configuration divide this group more than the model year does.

What you get ordering from us

• Genuine GM only. Every alternators listing carries the original factory part number.
• Fitment checked by a person. Send the VIN and we verify the alternators before the box leaves.
• Central shipping origin. Dallas keeps alternators transit times short nationwide.
• Backed after the sale. If your alternators does not work out, we make it right.

Avoiding the wrong part

The cheapest version of a part is rarely the cheapest repair once labor is counted twice. The VIN decodes the build sheet, which is the only place option content is recorded reliably. We hold deep stock, so same day dispatch is the norm rather than the exception.