Ford F-150 tail light wiring colors: 2008 to 2021 (with halogen vs LED differences)
Wire color reference for Ford F-150 tail lights from the 12th, 13th, and 14th generations. Includes the halogen vs LED differences on 2015 to 2020 trucks, the ground wire variants, and the bulb housings that don't drop in across generations.
If you’re splicing into a stock F-150 tail light harness, the wire colors changed twice in the 12th-to-14th generation run, and LED versus halogen trucks within the same year use different colors for the same circuit. Get the wrong wire and you’ve connected a turn signal to a reverse circuit. Here’s the color reference for each generation, with the differences called out.
Quick reference: which generation is your truck?
| Years | Generation | Notes |
|---|---|---|
| 2009 to 2014 | 12th gen | Mostly halogen factory tail lights, simpler 4-wire harness |
| 2015 to 2020 | 13th gen | Aluminum body, LED option starts. Halogen and LED have different wire colors |
| 2021 onward | 14th gen | LED standard. BCM-controlled, harder to splice into without dropouts |
The 2008 model year is technically still 11th gen and uses a slightly different harness than the 2009 to 2014 trucks. If you have a 2008, double-check colors at the connector with a meter before splicing.
2009 to 2014 F-150 tail light wires
The 12th gen harness has four wires per side:
| Function | Wire color |
|---|---|
| Parking / running light | Yellow with green tracer |
| Left rear turn / brake | Gray with brown tracer |
| Right rear turn / brake | Pink with orange tracer |
| Ground | Black |
Both sides combine the brake and turn signal on the same wire (a common dual-filament setup). If you’re adding a third brake light or LED light bar, the simplest tap point is the running light wire for steady on and the turn wire for flashing.
2015 to 2020 F-150 (halogen tail lights)
The 13th gen redesigned the harness. The halogen wire colors are:
| Function | Factory wire color | Common light-bar pigtail color |
|---|---|---|
| Driver-side turn | Green with orange tracer | Yellow |
| Driver-side running | Light blue with gray tracer | Brown |
| Passenger-side turn | Green with orange tracer | Green |
| Driver-side reverse | Green with brown tracer | White |
| Power (12V) | Orange | Red |
| Ground | White | Black |
Note that both turn signals share the same factory color (green with orange tracer). To tell the driver and passenger wires apart, follow the harness back to the body splice or test with a meter while a helper cycles the signals.
2015 to 2020 F-150 (LED tail lights)
The LED version uses different colors on three of the wires:
| Function | Factory wire color | Common light-bar pigtail color |
|---|---|---|
| Driver-side turn | Green with blue tracer | Yellow |
| Driver-side running | Blue with gray tracer | Brown |
| Passenger-side turn | Blue with orange tracer | Green |
| Driver-side reverse | Green with brown tracer | White |
| Power (12V) | Orange | Red |
| Ground | White | Black |
The LED trucks have different colors for driver-side and passenger-side turn, so identification is easier. The running light wire is also blue (not light blue) on the LED version.
If you have a 2015 to 2020 truck and you’re not sure whether it’s halogen or LED, pull the lens off and look. Halogen uses a screw-in bulb that turns counterclockwise to remove. LED uses a sealed assembly with a pigtail connector on the back.
2021 onward (14th gen)
The 14th gen LED tail lights are controlled by the body control module, not by direct power-and-ground. The BCM PWM-controls (pulse-width modulates) the LED arrays to brighten and dim them. Splicing into one of these harnesses to drive an aftermarket light bar usually doesn’t work cleanly. The LED bar either flickers or won’t light at all because it sees a PWM signal, not a constant 12V.
For 14th gen trucks, the standard workaround is to tap the wiring at the trailer-tow connector or the high-mount stop light instead. Those circuits are still standard 12V switched and behave normally with aftermarket loads.
How to replace a bulb (2009 to 2020 halogen)
For trucks with screw-in halogen bulbs, the process is the same across generations:
- Open the tailgate. Locate the two bolts holding the tail light housing to the body. They’re 5/16” hex head.
- Loosen and remove both bolts. Set them aside.
- Pull the housing straight back to release it from the body clips. It comes free with maybe an inch of harness slack.
- Twist the bulb socket counterclockwise about a quarter turn. The socket releases from the back of the housing.
- Pull the old bulb straight out of the socket. Don’t twist it; these are pull-out, not screw-out.
- Insert the new bulb. Reinsert the socket and twist clockwise to lock.
- Test the new bulb before reinstalling the housing.
- Reseat the housing, reinstall the bolts. Don’t overtighten or you’ll crack the lens.
For LED housings (sealed assemblies with no replaceable bulb), the whole housing is the replacement part. Most are direct bolt-in if you keep the same generation and trim level.
Bulb numbers if you’re stuck without the box
| Function | 12th gen (2009 to 2014) | 13th gen halogen (2015 to 2020) |
|---|---|---|
| Brake / tail | 3157 (dual filament) | 3157 |
| Turn signal | 3157 | 3157 (some trims), 7440 (others) |
| Reverse / backup | 3157 | 921 |
| License plate | 168 | 168 |
If your truck has LED tail lights, none of these apply. The assembly is sealed.
Common wiring faults on F-150 tail lights
One side dim, other side normal: ground fault on the dim side. The white ground wire is corroded at the housing or where it bolts to the chassis. Clean the contact, sand any paint or rust off the chassis mount, and reattach.
Both lights flicker when engine is running: a charging system issue, not a tail light issue. Check the alternator and battery before chasing wiring.
Brake works, turn doesn’t (or vice versa): the 3157 bulb has two filaments. If one filament is burned out but the other is fine, you’ll get exactly this symptom. Replace the bulb before testing the wiring.
Trailer plug works, tail lights don’t (or vice versa): these are separate circuits on F-150s with the factory tow package. A trailer-tow fuse can blow and kill the trailer plug while leaving the truck’s tail lights intact. Check both fuses.
When you actually need a professional
Bulb replacement and clean splicing into a halogen harness are routine driveway jobs. Splicing into a 14th gen LED harness, replacing a body control module, or chasing an intermittent fault that doesn’t show up at rest are the cases where dealer or independent shop time pays for itself. The shop has the FDRS scan tool that talks to the BCM directly, which is the only way to confirm a module fault versus a wiring fault on later trucks.