2021 GMC Sierra 3500 Electrical Parts

This table covers the alternators that charge the battery and run the electrical load. Typical signs include dim lights at idle, a battery lamp, or a growl from the charging pulley. Load-test the battery and inspect the belt and grounds — a bad ground mimics a failed alternator. Read more

6 Alternator / Generator parts for the 2021 GMC Sierra 3500 come from 4 brands — GM GENUINE, FVP, PURE ENERGY and 1 other brand. The "Popular" part is GM GENUINE 85671415.

The New section lists 2 options from GM GENUINE — brand-new units rather than rebuilt ones. GM GENUINE 85671415 is listed in this group.

The Remanufactured section lists 4 options from FVP, PURE ENERGY and TERREPOWER — factory-rebuilt units with new wear components. FVP 10394 is listed in this group.

This group includes GM GENUINE 85671415, GM GENUINE 13563314 and FVP 10394 and the remaining parts above.

This table covers the brackets that mount the Alternator / Generator. Typical signs include a cracked mount, a rattle, or a bracket that no longer holds alignment. Confirm position in the notes. Many brackets look alike and bolt to different corners. Read more

This group shows a single part: GM GENUINE 97356246.

This table covers the Alternator / Generator bushings. Typical signs include a clunk over bumps, or a torn or walked-out bushing you can see. Press the new bushing square. A cocked bushing will tear in a few thousand miles. Read more

2 Alternator / Generator Bushing parts for the 2021 GMC Sierra 3500 come from GM GENUINE.

Part numbers include GM GENUINE 12624586 and GM GENUINE 12623219.

This table covers the pulleys on the alternator shaft. Typical signs include a growl or chirp that follows engine speed, or a pulley that will not spin freely by hand. Spin each pulley with the belt off. Roughness or play means replace it with the belt. Read more

3 Alternator / Generator Pulley parts are listed for the 2021 GMC Sierra 3500, from LITENS and CONTINENTAL.

This group includes CONTINENTAL 49903, LITENS 920112A and LITENS 920111A.

This table covers the Anti-Theft control modules. Read more

GM GENUINE supplies both parts for the 2021 GMC Sierra 3500.

This group includes GM GENUINE 13516351 and GM GENUINE 13516352.

This table covers the batteries listed by group size and specification. Typical signs include slow cranking, a battery lamp, or a no-start after the vehicle sat overnight. Confirm group size and terminal layout in the notes. Clean the posts and the ground before condemning the battery. Read more

7 Battery parts are listed for the 2021 GMC Sierra 3500, from FVP, DEKA, LUCAS and 3 other brands. DEKA 9A48 carries the "Popular" badge.

Listed part numbers: DEKA 9A48, LUCAS LBAGM004A and ACDELCO 48AGM, plus the other parts above.

This table covers the positive and ground cables that run from the battery. Typical signs include a stretched or frayed cable, or a control that no longer reaches the end of its travel. Route the new cable through the same clips. A kinked cable binds and fails early. Read more

5 Battery Cable parts for the 2021 GMC Sierra 3500 come from GM GENUINE. The "Popular" part is GM GENUINE 84794790.

Listed part numbers: GM GENUINE 84794790, GM GENUINE 87866332 and GM GENUINE 84772924, plus the other parts above.

This table covers the Battery Cable Terminal ends. Read more

One part is listed for the 2021 GMC Sierra 3500 — GM GENUINE 84335255.

This table covers the Battery Current sensors. Typical signs include a warning lamp, a stored code, or a reading that drops out when the harness is wiggled. Inspect the connector and ground before replacing the sensor — wiring faults are often condemned as bad sensors. Read more

This group shows a single part: STANDARD MOTOR PRODUCTS SBC111.

This table covers the Battery Terminal Bolt nuts. Read more

This group shows a single part: GM GENUINE 11570961.

This table covers the Blind Spot Detection sensors. Typical signs include a warning lamp, a stored code, or a reading that drops out when the harness is wiggled. Inspect the connector and ground before replacing the sensor — wiring faults are often condemned as bad sensors. Read more

2 Blind Spot Detection Sensor parts for the 2021 GMC Sierra 3500 come from HELLA.

Part numbers include HELLA 013068241 and HELLA 013068041.

This table covers the body-control modules that run lighting, locks and wipers. Read more

2 Body Control Module (BCM) parts for the 2021 GMC Sierra 3500 come from GM GENUINE.

This group includes GM GENUINE 13531840 and GM GENUINE 84652297.

This table covers the resettable circuit breakers in this vehicle's electrical system. Read more

STANDARD MOTOR PRODUCTS supplies both parts for the 2021 GMC Sierra 3500.

Listed part numbers: STANDARD MOTOR PRODUCTS FH58 and STANDARD MOTOR PRODUCTS FH59.

This table covers the engine-control modules that run fuel, spark and emissions. Read more

This group shows a single part: GM GENUINE 12720006.

This table covers the replacement fuses for this vehicle's fuse boxes. Typical signs include one circuit dead while its neighbor still works, or a fuse that blows again as soon as you replace it. Match amperage and fuse type. A repeat blow means a short — find it before the next fuse. Read more

43 Fuse parts are listed for the 2021 GMC Sierra 3500, from GM GENUINE, BUSSMANN and ACDELCO. GM GENUINE 15305191 carries the "Popular" badge. They are grouped as 10 Amp, 100 Amp, 125 Amp, 15 Amp, 150 Amp, 175 Amp, 2 Amp, 20 Amp, 225 Amp, 25 Amp, 250 Amp, 3 Amp, 30 Amp, 300 Amp, 350 Amp, 4 Amp, 40 Amp, 450 Amp, 5 Amp, 50 Amp, 60 Amp, 7.5 Amp and 70 Amp, with 25 Amp the largest group at 5 parts from ACDELCO, BUSSMANN and GM GENUINE.

This table covers the horns mounted in the front of the vehicle. Read more

One part is listed for the 2021 GMC Sierra 3500 — GM GENUINE 85130076.

This table covers the Jumper cables. Typical signs include a stretched or frayed cable, or a control that no longer reaches the end of its travel. Route the new cable through the same clips. A kinked cable binds and fails early. Read more

2 Jumper Cable parts for the 2021 GMC Sierra 3500 come from GM GENUINE.

Listed part numbers: GM GENUINE 84655051 and GM GENUINE 84735810.

This table covers the receivers that pick up the key-fob unlock signal. Read more

2 Keyless Entry Module / Receiver parts for the 2021 GMC Sierra 3500 come from GM GENUINE.

Part numbers include GM GENUINE 13523298 and GM GENUINE 13558725.

This table covers the key fobs that lock, unlock and start the vehicle. Read more

8 Keyless Entry Remote parts for the 2021 GMC Sierra 3500 come from 2 brands — GM GENUINE and DORMAN. The "Popular" part is GM GENUINE 22881479.

Listed part numbers: GM GENUINE 22881479, GM GENUINE 84209236 and DORMAN 99444ST, plus the other parts above.

This table covers the replacement shells for the key fob. Read more

This group shows a single part: DORMAN 95642.

This table covers the Park Assist (PAS) Camera modules. Typical signs include a cluster of unrelated faults, a no-communication code, or a module that will not sleep. Confirm power, ground and programming compatibility in the notes. Modules are rarely plug-and-play across years. Read more

One part is listed for the 2021 GMC Sierra 3500 — GM GENUINE 84716060.