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.

A: Lighting problems like this can seem very c...

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: My engine idle is high when I start my car

If the idle shoots up just after startup then drops down, this is not usually a major cause for concern, and often normal. Although 2000 rpm does seem a little high, 1500 rpm isn't really to out of the ordinary,...

Q: HVAC

You need to have the fan clutch checked to see if it is pulling air at idle. If the fan clutch is not locking up then it needs replaced. If the fan clutch is okay then the pressures will need...

Q: Lights and blinkers not working.

The AC wire can be fixed but would have to be checked to see if a fan is broken first. I would recommend having a mechanic, like the certified ones at YourMechanic, come and check it out for you to...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...