2013 GMC Sierra 2500 HD Alternators

Genuine GM alternators for the 2013 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.

What sends people here

A battery light, dimming headlights at idle, or a no-start after a short drive. On a heavy duty pickup, cab configuration, drivetrain and box length all split this group, so the badge on the tailgate is not enough to order from.

Why buy OEM here

• Wholesale pricing. Most alternators numbers land well below dealer list.
• No aftermarket substitutes. These are GM alternators, not OE-style equivalents.
• We catch the wrong part before you do. VIN verification is free on every alternators order.

Before you order

OEM components carry GM warranty coverage, which is usually worth more than the price gap on the invoice. If you are unsure which version you have, give us the VIN and our specialists will confirm fitment. Stock moves out the door the day you order it, assuming you beat the mid-afternoon cutoff.