Right Turn Signal dont work with headlights on!!HELP
 

Right Turn Signal dont work with headlights on!!HELP
Has anybody had this problem before, i know one other truck 08 f350 that has the same problem only other side.
My turn signal blinks fast on the right side but all lights work, when the headlights are on or parking lights the front right blinker doesnt work. I dont know what to do?

Is it still under warranty? If yes, take it to the dealer. If not, try a new bulb.

The bulb works, No warranty

If all the bulbs are good you probably have a bad flasher

sounds like the flasher to me if it is flashing really fast. Change that and then tell us if that fixed it.

My '08 has gone through about 6 rear bulbs in 40,000 miles. Usually its the left turn signal, but the right one does it also, just not as much. The brake and tail light portion of the bulb works (notice, the rear has only one bulb for brake, turn and tail), but the turn is the one that goes. And there are heat marks at the base of the bulb. Like it was sitting on a heater. Scorch marks actually. I had it looked at and was told that was normal. BS. So now I carry a pack of bulbs and a nutdriver with me. In fact, yesterday I hit the blinker and she started the fast dance, which is my indication that the bulb has blown the flasher portion. Changed it out and I'm good for another 8k or so. Ridiculous I know, but with the dealer stating its normal, even though I dont believe them, I have no recourse. Tired of arguing with these guys.

You must have a short. The dealers don't care enough sometimes to look for the real problem. I would just track the harness going up to that light, and look for any points where it could be pinched, or rubbing. Just an idea.

Should be pretty easy to remove the light and fixture and look at those wires to see if they are rubbing.

moved to Super Duty