🔧 Rear Turn Signal Bulb - Bulb Replacement

The rear turn signal bulb in your Sierra is replaced by removing the tail lamp assembly, then swapping the bulb from the back of the lamp. This is a quick job, but the tail lamp tabs can be tight, so work slowly to avoid cracking the lens.

Difficulty Level: Beginner | Estimated Time: 0.5-1 hour

---

⚠️ Safety & Precautions

• Turn the lights off and remove the key/fob before starting.
• Let the bulbs cool if the truck was just running lights.
• Handle the new bulb with clean gloves. Oil from your fingers can shorten bulb life.
• Do not force the tail lamp assembly. The guide pins and clips can break if pulled at an angle.

---

🔧 Required Tools

You'll need the following tools for this repair:

• 7mm socket
• Ratchet
• Trim panel tool
• Gloves
• Safety glasses

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Rear turn signal bulb - Qty: 1
• Bulb socket seal - Qty: 1

---

📋 Before You Begin

• Park on a flat surface and shift into Park.
• Set the parking brake.
• Turn the headlight switch off.
• Open the tailgate for easier access to the rear lamp fasteners.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Open the tailgate and locate the tail lamp fasteners

• Open the tailgate fully.
• Look at the inside edge of the rear tail lamp assembly.
• You will see the retaining screws securing the lamp to the body.

Step 2: Remove the tail lamp retaining screws

• Use a 7mm socket and ratchet to remove the tail lamp screws.
• Keep the screws in a safe place.
• Do not pry on the lens.

Step 3: Release the tail lamp assembly

• Grip the tail lamp assembly with both hands.
• Pull straight rearward to release the locating pins from the body.
• If it sticks, use a trim panel tool very gently at the edge.
• Do not twist the lamp housing.

Step 4: Remove the bulb socket

• Reach behind the tail lamp and find the turn signal bulb socket.
• Rotate the socket counterclockwise and pull it out.
• Pull the old bulb straight out of the socket.

Step 5: Install the new bulb

• Push the new rear turn signal bulb into the socket.
• Make sure it seats fully and evenly.
• If the socket seal is cracked or swollen, replace it now.

Step 6: Reinstall the bulb socket and tail lamp

• Insert the socket back into the tail lamp housing.
• Rotate it clockwise until it locks.
• Align the tail lamp pins with the body holes and press the lamp into place.
• Reinstall the 7mm screws and snug them down.
• Torque to 3 Nm (27 in-lbs).

Step 7: Test the new bulb

• Turn the ignition on.
• Activate the left and right turn signals one at a time.
• Check that the new bulb flashes normally and matches the other side.
• Close the tailgate after confirming operation.

---

✅ After Repair

• Verify both rear turn signals flash at normal speed.
• Check the brake lights and tail lights while you are there.
• If the dash shows a bulb-out message, recheck the socket seating and bulb type.

---

💰 DIY vs Shop Cost

Shop Cost: $80-$160 (parts + labor)

DIY Cost: $10-$35 (parts only)

You Save: $70-$125 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1 hour.

---

🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.