02 F 150 V8 4.6L rear driverside blinker does not work and blinker signal on dash flashes 10x faster than the right side signal HELP?

Probably a burned out bulb. Many vehicles do that to draw attention to the fact that a bulb is burned out. it blinks realy fast just to let you know the light bulb is out. turn on your emergency flashers, look at all the lights to see which one is not blinking and replace it, you will be good as new. It sounds like you have a faulty bulb, and the system is signaling you.