2017 f250 with stock quad beam LEDs. Cannot figure out why my driver blinker doesnt work. No other lighting issues I can find and even replaced the headlight and LCM and had no luck. Any ideas would be greatly appreciated before I have to take to the dealer. It does fast blink on the dash indicating something is wrong somewhere. Just cannot figure out where.

 

So first question have you added blinker fluid?

Ok thats out the way lol. It seems you have tried all the likely parts. I would say check the manual first and make sure the light doesn’t have its own fuse or relay for some reason. Next I would think would be wiring. I would recommend checking for corrosion at the headlight connection. See if you can get a hold of the wiring schematic.

I did see this on a 23’ and it was a software issue not sure it applies but just a thought.