F-150 - Rear Turn Signal Bulb Replacement 💡

Nice and beginner-friendly job on your F-150. I’ll walk you through it step by step.

Parts & Bulb Type 🔧

• 💡 Rear turn signal bulb (2016 F-150 usually uses a 3157A amber bulb for rear turn signals in the tail lamp).
  • If your rear turn signal is amber, use an amber 3157A.
  • If it’s red (less common), it may share a red brake/turn bulb (3157). Check the color when you remove it.
• 💡 It’s smart to replace both rear turn bulbs at the same time so brightness and color match.

Tools You’ll Need 🧰

• 🛠️ 8 mm socket and ratchet (or nut driver) – for tail lamp screws.
• 🛠️ Short extension (2–3") – makes reaching the screws easier.
• 🛠️ Flat plastic trim tool (or an old plastic card) – to gently pry the lamp if it’s stuck; avoids scratching paint.
• 🧤 Gloves – keep oils from your skin off the bulbs and protect your hands.
• 🧽 Clean rag – to wipe dirt away from the lamp area.

Safety First ⚠️

• ⚠️ Park on a flat surface, set the parking brake, and put the transmission in PARK.
• ⚠️ Turn the ignition off and make sure the lights and turn signals are off.
• ⚠️ Don’t force the tail lamp; it’s held by clips that can break if you yank it.

Step-by-Step: Remove Tail Lamp 🪛

These steps are the same for left and right sides.

• 🔧 1. Open the tailgate
  • Open the tailgate fully. You’ll see two vertical screws on the inside edge of each tail lamp (facing the tailgate).
• 🔧 2. Remove the tail lamp screws
  • Use the 8 mm socket and ratchet to remove the two screws holding the tail lamp.
  • Set the screws somewhere safe so they don’t roll away.
• 🔧 3. Pull the tail lamp straight back
  • Hold the lamp with both hands.
  • Pull it straight back toward you (away from the truck bed). It’s located on two plastic alignment pins that fit into grommets.
  • If it’s stuck, gently wiggle side to side while pulling back. Use a plastic trim tool at the outer edge if needed. Do not pry with a screwdriver on the paint.
  • Once free, support the lamp so it doesn’t hang by the wires.

Identify & Remove the Turn Signal Bulb 💡

• 💡 4. Find the turn signal socket
  • On the back of the tail lamp you’ll see multiple bulb sockets.
  • On most 2016 F-150s:
    • Top socket = tail/stop (brake) light.
    • Middle or lower socket = turn signal (often amber bulb).
  • If unsure, look through the lens from the front to see which bulb lines up with the amber section.
• 💡 5. Remove the bulb socket
  • Grip the socket and turn it about ¼ turn counterclockwise (left) until it stops.
  • Pull the socket straight out of the tail lamp housing.
• 💡 6. Remove the old bulb
  • The 3157-style bulb is a push-in wedge bulb (no twist base).
  • Hold the socket and pull the bulb straight out. Wiggle gently if it’s tight.

Install the New Bulb ✅

• ✅ 7. Install the new bulb
  • With gloves on, line up the new bulb’s metal contacts with the socket slots.
  • Push the bulb straight into the socket until it’s fully seated.
• ✅ 8. Reinstall the socket into the tail lamp
  • Align the tabs on the socket with the openings in the tail lamp.
  • Insert the socket and turn it ¼ turn clockwise (right) until it locks.

Reinstall the Tail Lamp 🔩

• 🔩 9. Position the tail lamp
  • Line up the two plastic alignment pins on the lamp with the holes in the truck body.
  • Push the lamp straight in until it sits flush with the body.
• 🔩 10. Install the screws
  • Reinstall the two 8 mm screws by hand first so they don’t cross-thread.
  • Tighten with the ratchet until snug. Do not overtighten—they’re going into plastic.
    • Typical torque is about 25–35 in-lb (just past “snug” with a small ratchet).

Test the New Bulb 🧪

• 🧪 11. Check operation
  • Turn the ignition to RUN (engine can be off).
  • Turn on the left or right turn signal for the side you replaced.
  • Walk to the back and confirm the turn signal flashes normally and is bright.
  • Also check the hazard lights to be sure both sides work.

Tips & Tricks 💡

• 💡 If the turn signal flashes very fast after replacement, the bulb may not be seated correctly or may be the wrong type.
• 💡 If the socket looks burned or melted, it should be replaced; heat and corrosion can cause poor contact.
• 💡 Do both sides now so you don’t have to repeat the job soon.

If you’d like, tell me which side (left/right) you’re doing and whether your rear turn signal section is amber or red, and I can confirm the exact bulb number for your truck.

HowToo makes it easy: below this answer you’ll see the correct bulbs and any tools you might need. You can add them to your cart right from the parts section for fast shipping. 🚚