Turning signals will work only when emergency flasher switch is set to the on position /also the emergency flashers do not work at all/

1. Do your emergency flashers work?
Check all your fuses, make sure they are getting a good contact.
If your emergency flashers work, it may be a faulty turn signal switch.
If your emergency flashers work that will eliminate the flasher. The one flasher works both turn and emergency signals.

try to test turn signal switch, which its the live wire is not sending signal to the flasher.

The flasher relay is mounted in the main fuse panel under the dash, driver's side.Are the lights coming on at all, or is there nothing ? it is possible that you may have a bad ground wire to the signals. Do the emergency hazards work ( lighting up and flashing?)If so, then your ground is good and it could very well be the flasher. You should be able to switch the emergency flasher for the turn flasher for a test of the circuit. The flashers should be mounted side by side in the fuse panel - just exchange them and test. If so, keep the emergency flasher there and take the turn flasher in to replace. The parameters should be the same so you can just leave the E. flasher relay in place and out the turn flasher where the E. flasher was.

The emergency flasher switch is also the turn signal flasher It pops out of the dash and can be replaced easy. do chaeck the fuses before going to this much troble. check all the fuses as some work backup circuits that you wouldn;t think would be important. Before replacing the flasher switch ( you may only be able to buy it from the dealer) work the switch several times and the flashers will come on cheak to see if allthe lights work thenturn the flashers off and see ( with the key on if the turn signals now work. Now if during the test with the four way flashers you see a bulb or more out you know that the turn signals wouldn't work, but the four ways will. they work on different fuses so chak the turnsignal fuse too. after cycling the switch try the turn signals again as the switch is likly to stick and sometimes cycling it will get the turn signals working again. Fooling around with the switch you may find a position that the turn signals work. if you can't get it to stay working then you'll have to change the flasher emergency switch.

The emergency flasher and the turn signal flasher are two separate items. You could have a defective T/S flasher.

Sounds like a multifunction switch, work the emergency flasher button up and down a few times, then attempt to work the turn signals if the signals work then you will need a multifunction switch.

Your signals work on a seperate system then your flashers. Sounds like your multifunction switch is busted.

Look in the fuse panel and the turn signal flasher is the big round most likely yellow or silver in the corner of fuse panel. The emergency flasher is in the back side of fuse panel right directly behind the turn signal flasher.
Remove the emergency flasher and install it in place of the turn signal flasher and see if this corrects the problem and if so get a new flasher. If this does not correct it problem will most likely be the multi-function switch.

Your F--150 has 2 flashers, emergency and turn signal. Both are mounted on the fuse block under the dash. The turn signal flasher is mounted on the front of the fuse panel, the emergency flasher is mounted on the rear of the fuse panel. so replace the turn signal flasher should solve the problem. Let me know how it goes.

Check the flasher under the dash to the left of the steering column. It's got about 8 or 10 wires plugged into it.