Skip the auto shop - Our mechanics make house calls

Q: Rear Brake light and turn signal not working on driver side

asked by on

2011 F-150 Platinum. The rear brake light and turn signal is not working on the driver side. I have replaced the bulbs and the connectors but to no avail. I checked the fuses and they are fine as well. When I take my electronic key and unlock the truck the driver rear lights will not light up but when I lock the doors it does light up in the back. Need Help.... Never have seen this before.
My car has an automatic transmission.

Lighting problems like this can seem very confusing, so it is best to start with the basics. Check for power and ground at the turn and brake light sockets. I suspect in your case you will have a good ground but you won’t have any power. If you discover there is a bad ground, this will be the simplest repair. The power side of these lamp circuit is from the BCM. (body control module) So if you don’t have power at the sockets, you will need to locate the BCM and check for power coming out of the BCM.

Before you do that, you will need to connect a scanner that can communicate with the BCM. Believe it or not, you could have a BCM code that is stopping your brake and turn signal lights from working. Most people don’t have access to a scanner that can access the BCM, so you will most likely need to book an appointment with us to do this. If there are no codes in the BCM, it is most likely the BCM that needs to be replaced. Before I went and replaced it, I would check all the power and grounds at the BCM.

BCM’s are common failure items on Fords, so it is likely the problem. But you will want to do due diligence and communicate with the BCM. I recommend the following inspection to help you out. Electrical components are not working

Be sure to send the technician a note about your exact issue so he or she can come best prepared for your repair.

Good luck!

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: MISFIRE CYLINDER NUMBER 3

Hi There, There are several reasons that can cause a valve to burn. One is normal wear and tear. As miles are put on an engine, the constant pounding and heat erosion wears away the metal on the face of...

Q: Trucks starts up but have to give gas to keep running then dies starts up a second time then it will stay running.

It sounds like you may have a dirty or failing idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and...

Q: Turn signal comes off ocassionally - 2000 BMW 328Ci

Hello. It sounds like you have a problem with the turn signal switch or the socket that the turn signal bulb goes into. If there is a problem with the fuse, it usually causes a problem that is not intermittent,...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...