Fits:
- 2014-2018 GMC Sierra 1500
- 2019 GMC Sierra 1500 Limited
- 2015-2019 GMC Sierra 2500HD / 3500HD
Does not fit 2019-and-newer Sierra 1500 other than the 2019 Sierra 1500 Limited — the Limited is the carry-over body, and it is the only 2019 1500 this set covers.
Two Things to Know Before You Start
1. The adapter harness is a year thing. 2014-2015 trucks use the adapter harness included in the box. 2016 and later trucks plug into the factory connector directly — no adapter.
2. There is no amber turn signal, and that is correct. Brake and turn share the same red lighting zone on this product, and the turn signal flashes red. That matches the factory lamp. It is the intended behaviour, not a fault.
Before You Start
- Park on level ground, switch off, and disconnect the negative battery terminal while handling wiring.
- Use masking tape near painted edges around the tailgate and bed sides.
- Do not put dielectric or weather-sealing grease on connectors or sockets.
- If a lamp does not move, stop and look for another fastener or locating pin.
Required Tools
- Trim removal tool
- Metric socket and ratchet set
- Phillips and flat screwdrivers
- Masking tape and clean microfiber towels
- Electrical tape and zip ties for the supplied harness
- A helper for brake light, turn signal and reverse light testing
Part 1: Remove the Factory Tail Lights
Step 1: Lower the Tailgate
Locate the lamp retainers.
Step 2: Support and Unfasten
Hold the lamp while removing its fasteners.
Step 3: Pull It Straight Out
Release the locating pins by pulling in line with the lamp. Do not lever against a painted panel.
Step 4: Disconnect
Press the lock tab and pull on the connector body, not on the wires.
Step 5: Compare Before Fitting
Set the old and new lamp side by side and check the rear plug and the mounting points before committing to the swap.
Part 2: Install the New Tail Lights
Step 6: Fit the Adapter — 2014-2015 Trucks Only
Connect the included adapter harness to the vehicle connector first, then to the lamp. Skip this step entirely on 2016 and later trucks.
Step 7: Connect the Lamp
Seat the connector fully and confirm the lock tab clicks home.
Step 8: Seat the Lamp Evenly
Align the locating pins and check the body gaps before tightening. Do not overtighten plastic mounting points.
Step 9: Test Before Closing Up
- Running lights on both sides.
- Brake lights, with a helper on the pedal.
- Left and right turn signals and hazards. The turn signal flashes red, in the same zone as the brake light.
- Reverse lights, with the truck safely in reverse and the parking brake on.
- Startup animation, once the road-light functions pass.
- Check for dashboard warnings, hyperflash or flicker.
Common Issues and Solutions
The lamp does not light on a 2014-2015 truck. The adapter harness is missing or not seated. Confirm it is fitted and locked at both ends.
There is no amber turn signal. Expected. This product flashes the turn signal red in the brake zone, matching the factory lamp.
One function does not work. Verify the connector is fully seated.
Warning, flicker or hyperflash. Confirm you installed the correct product for your year, and that every connector is seated.
The lamp will not sit flush. Check for a trapped harness and confirm every locating pin has seated.
Condensation inside the tail light. Temperature differences can cause light condensation, which is normal. Once the light has been on for a while and the internal temperature stabilizes, the moisture clears on its own. It does not affect brightness, performance, or lifespan.
