electrical

Turn Signal Bulb - Front

for 2017 Ford F-150 3.5L V6 EcoBoost · RWD

Editorial review:Chris Hackleman — Master Technician · 20+ years · Jeff Moore — Master Lexus & Toyota Mechanic · 20+ years

Difficulty

Easy

Time

12 min

Tools

Steps

✓Expert-verified. Personally reviewed and approved by OLP's master technicians (Chris Hackleman & Jeff Moore — 20+ years each). Always follow the vehicle's factory service information and torque specs.

This procedure covers replacement of the front turn signal bulb on a 2015-2020 Ford F-150 with 3.5L EcoBoost engine, accessed from the engine bay.

Warnings

⚠Allow headlight assembly to cool completely if vehicle was recently operated to avoid burns

ℹ️Do not touch halogen bulb glass with bare hands as skin oils can cause premature failure; use clean gloves or tissue

Tools required

Socket wrench set

Flathead screwdriver

Work gloves

Parts

Front turn signal bulb (3457A amber) × 1 — Use OEM specification or equivalent 3457A amber bulb

Preparation

Park vehicle on level surface and turn off ignition
Allow headlight assembly to cool if vehicle was recently driven
Open hood and secure with prop rod
Locate the headlight assembly on the side requiring bulb replacement

Procedure

1
Access the turn signal bulb socket
Locate the turn signal bulb socket at the outboard side of the headlight assembly. The turn signal socket is the outermost bulb position when viewing from the front of the vehicle. You may need to move aside wiring harnesses or air inlet ducting for better access on the driver side.
2
Remove the bulb socket
Rotate the turn signal bulb socket counterclockwise approximately 1/4 turn (90 degrees) until it releases from the headlight housing. Pull the socket straight out from the headlight assembly with gentle, even pressure.
3
Remove the old bulb
With the socket removed, grasp the bulb firmly and pull it straight out of the socket. The bulb uses a wedge-style base and does not twist. If bulb is stuck, gently wiggle while pulling to release. Inspect the socket for any corrosion or damage.
4
Install the new bulb
Using a clean tissue or gloves to avoid touching the glass, align the new 3457A amber bulb with the socket. Push the bulb straight into the socket until it seats completely. The bulb should fit snugly without excessive force.
5
Reinstall the bulb socket
Insert the bulb socket back into the headlight housing, aligning the tabs on the socket with the slots in the housing. Push in firmly and rotate clockwise 1/4 turn (90 degrees) until the socket locks into place. Ensure the socket is fully seated and secure.

Reassembly

Reposition any wiring harnesses or ducting that was moved during the procedure
Close the hood securely

Verification

Turn ignition to the ON position without starting the engine
Activate the turn signal on the repaired side and verify the front turn signal blinks at normal speed
Activate the hazard lights and confirm both front turn signals flash synchronously
Visually inspect from outside the vehicle that the turn signal lamp illuminates amber with proper brightness
Verify the turn signal indicator on the instrument cluster flashes at normal speed (not rapid flash indicating a bad connection)

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