Need some info ,,,,, are you saying that the passenger side turn signal is ON all the time ,,just flashing all the time , cant shut it off ???? or that when you turn it on , it will not turn itself off after you turn the steering wheel???
and the drivers side turn signal does not come on at all,, you turn it on and nothing happens ????
we can go back and forth on this page
Ok,,, this sounds like a ground problem ,, something does not have a ground and is feeding back through the right turn signal ... so
do you have any after market headlamp bulbs in this unit ???
if you turn on the headlamps,, do all the exterior lamps work ok ????
do you notice by useing something on the car , like turning on the headlamps,, or turning on the a/c blower ,,, that the turn signal on the dash that is on ,, will cahnge its state ... ????
With not much to go on ,, I would start at the headlamp bulbs ,,, and access them and check there connectors for melting ,,, this unit is known for this ,,unplug the bulb and check its connectors
check all four ,,, also the ground for the r/f turn signal and headlamp is right by the headlamp ,, its a wire that is bolted to the body
thats about all I can think of right now, there is no known problems like this through Ford