I have all turn signals when the head lights are off tail lights work. NO brake lights, I replaced the brake light switch also. Is there a fuse?????
86 F150
Dustin

 

i believe there is a fuse for that but im not sure. does your e flashers work. i know when i was putting my 86 f250 together my brake lights would not come on when i pressed on the brakes. i replaced the switch an still no change. well from playing around, i found if you run a pos wire into one of the wires on the brake switch then it would work. im not sure what one out the two but on will cause the light to stay on and the other will only come on when you press the brake

 

dustin have you gave that tip a shot yet, did it fix the problem? hope she works soon for you