Where is the flasher relay on my truck my turn signal on the right is flashing fast?

Hello Gayle , your vehicle does not have a flasher relay . The flashers are controlled by a computer or module . The ford SJB - smart junction box fords body control module . What is the problem you are having ? No hazard lights , no turn signals - none at all ,or flashing real fast ?

Do you know how to do automotive electrical testing ? Do you know what a relay is and how it works ? Turn signals flashing fast , could be aburnt bulb , flasher module .
VEHICLE RELAYS Operation Diagnosis
Turn Signal Lamps
The HAZ LP fuse in the underhood fuse block supplies battery positive voltage to the multifunction hazard switch assembly. The TURN fuse in the IP fuse block supplies Ignition positive voltage to the multifunction turn signal switch assembly. With the ignition switch in the RUN or START position, ignition positive voltage is connected through the multifunction turn signal and hazard switch assembly to the flasher module which is grounded at G205. When the turn signal switch is placed in either the left or right position, the circuit is complete from the flasher module to the turn signal lamps and to ground. The flasher module then sends an on-off voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator. When the hazard switch is activated, all turn signal lamps will flash including both IPC turn indicators. The front turn signals are grounded at G111 and G112. The rear turn signals are grounded at G475 and G422 on the pickup and G450 on the utility.

If its flashing really fast and all lights on the circut are working you may need a heavy duty flasher as to location,depends on vehicle but they are usually close to the under dash fuse panel

That is a sign of a bad bulb, flashing fast. Check that rear bulb.

Replace the flasher relay. It is usually under the dash. Follow the clicking sound when the flasher is on. It just unplugs.

When its blinking fast look at both front and rear to verify which bulb isnt flashing. If the right works OK, then the flasher is OK. The flasher is INSIDE the front control module/integrated power module. If you cant find the problem, you may need a dealer to check it.

the flasher relay is located in the fuse panel, But you may want to check the front lights as well since all 4 of the blinkers are linked for the hazzard feature,any one of the bulbs can cause this issue.

under the dashboard

bad ground or bulb

Yes, This is easy. Recall on this problem. Take into dealer for free recall solution and it will stop.