I have a 2004 FX4 with 46k miles on it. Recently I have noticed the drivers side directionals acting funny. The directionals start blinking really fast as if a bulb is burnt out. Upon inspection it appears that all the directionals are working and not burnt out. Once I turn the directional off the amber light under the mirror stays on and only goes off when I turn the headlights off. Is this possibly caused by a bad flasher or is it a more serious electrical problem.

 

This is only the driver's side, the passenger side works fine ?

Is the directional illuminated when the headlamps are on, or with the parking lamps as well ?

 

Correct only the drivers side, the passenger side works fine. Directional stays on when the headlights are on.

 

Maybe someone else will have a suggestion, I cannot find any commonality for the headlamps and the issue with the mirror turn signal.

I found some if the parking lamps also caused it, but nothing with the headlamps alone.

 

Just double checked and it also does it with parking lights.

 

Did you ever find the solution to this? I am having this exact same problem right now. I replaced the muti function switch, swapped the relays around under the hood, checked the connections on the switch. Im stumped, anybody got any idears?

 

Knock on wood I got the problem to stop. I pulled the flasher and reinstalled it a few hours later. Also discovered I had a drivers side marker out which I replaced. Don't k ow if either had any direct relation but the problem stopped

 

Ok I'll give'r a shot. They started worked fine for me about half way to work yesterday am, then on the way home they weren't working right.

 

mine turned out to be a chaffed wire, about 6 in back from the bulb it had rubbed through, all fixed now. Thank you

 

I'm having almost this exact same issue. Very frustrating.