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2013 F150 Brake and Signal Light Issue

I’ve got a puzzle. I had LEDS in my 2013 to replace the original bulbs, and after a few random failed resistors, I decided to pull the LEDS out to convert back to stock. After I did this, I ran into a problem with the rear driver’s side tailight. The lights work as normal, but the turn signal and brake lights (higher intensity) do not work at all. I’ve got a hyperflash with the front turn signal bulb, which works with no issues. Any ideas on what may be causing it? I’m hoping it’s not a body control module.

what happens when you turn on the emergency flashers?


Flashers work normally on all 4 corners.

Then problem might be with the multi-function switch.


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how did you have the resistors in line for the LED’s? Have you removed them? Have you double checked the wiring around where they were?

Since the flasher function works okay this would mean the connection to the rear light is bad at the flasher switch. Try cycling that switch a few times to see if that helps.

Tried that and I am doubtful that it’s the multifunctional switch. The rear lights work but do not increase in intensity when the brakes are applied or when the turn signal is activated. Suspect it’s a wire issue with either a broken wire or loose connection somewhere or the Body control module. Definitely going to take someone to troubleshoot it.

If a short is detected by the BCM a fault may be set and the BCM may disable the affected circuit. Try disconnecting the battery for a moment.

I tried that to no avail. I wish I had a forscan

I’m thinking it is a short somewhere in the circuit…and I’m not electrical enough to trace it. Thanks for all the help everyone!

A shorting issue causes too much current to flow so it would blow a fuse. Your problem is due to a faulty connection to the rear light on that side of the truck. I’m not certain the BCM has anything to do with turning on the brake lights but it may. The brake lights run through the emergency flasher circuit and you stated that they work okay. So the wiring to the lights should be good. They use the brake lights along with the turn signals, for most vehicles at least, yours may be different. The trouble is most likely with the emergency flasher switch.

Does this vehicle have a lighting control module?

use a stick to prop the brake pedal down, then I presume what you see then is one side lower and the middle brake light working, and the other side lower one not working, right? if so try tapping w/your finger on the fixture and the bulb. If it briefly lights, you have a loose connection. I have that symptom on my Corolla for a rear side marker light, if it doesn’t light I just tap on the fixture, then it lights right up. discovering what’s wrong exactly for me will have to wait until the weather improves.