Hi, I got a 97 F250 diesel and I have a problem with the right side tail light sims like when I have the tail lights on the signal light won't blink and thats on the right side only. But with the tail lights off the signal light work just fine.

 

Have you changed the bulb?

 

Yes I have and still doing the same thing.I also went and found the orange wire inside the truck which is the signal light one on the right side and tested it with a 12v tester and when the tail lights are off the tester blinks just fine but a soon as I pull the head light switch the tester stops blinking