Rear passenger brake/turn signal quit working,

[Raptorick]

So the turn signal brake light quit working and the dealer said the unit needs replaced , so I bought some aftermarket blacked out ones and replaced both sides, I still dont have turn signal and brake light, now I am wondering if there is a module that controls them or if there is a ground or something, any ideas other then blinker fluid helps

 

[FordTechOne]

The turn signal and brake light are powered by a transistor in the Body Control Module. Since they’re not working there should be DTCs stores in the module. Do you have ForScan? Also, verify there is nothing aftermarket tied into the BCM or lighting circuits. The BCM will see that as overcurrent and disable the output.

 

[Raptorick]

Thanks for the response, I will be running to the dealership tomorrow and will use this information as the starting point, Much appreciated,

 

[smurfslayer]

What he said. I tripped the BCM trying to pull relay power off the bed light circuit. I believe that’s ... 22 gauge wire? anyway I thought it would be ok, but the truck thought otherwise. It doesn’t blow a fuse, the BCM throws a fault and disables the circuit.

Lesson learned. I did not remember the brakes / rear lights being out but I do remember the 3rd light on the cab was out, along with the bed lights. I cleared the DTCs and got power from up front of the truck, like I should have all along and moved on.

Good luck