replacing bulbs with LEDs
 

I tried to replace my stock tail/turning signal lights with LEDs. They worked....sorta. By that I mean they lit up but they wouldn't blink for the turn signals. Also the blinker control went nuts, it started buzzing and the blinking way to fast. Needless to say I put the bulbs back in. Does anyone know how to make these things work right?

From what I understand, the standard flasher is designed to flash the standard bulbs based on the electrical current drawn by the bulbs themselves; therefore, since the LED type bulbs draw a MUCH lesser current, it causes the flasher to flash much quicker. Look at it this way. Let's say that one of your standard bulbs actually blew out. In the F-150 this causes the flasher to flash much faster, because less current is being drawn for the bulb. I have dealt with this on my F-150 already. You might check to see if there is an aftermarket flasher designed for LED's.

hixon is correct. The flasher works in heating a bimetalic strip arm, from the bulb current passing through a heating wire that make the metal curl and open the connection. Then it fast cools and makes again. This is the flasher action.
The LED bulbs don't draw enough current to make the flasher work at rated speed.
Same if a wrong bulb wattage is used or one bulb blows out.

solid state flasher
 

Hi.

Go buy a solid state flasher. These operate regardless of bulb load .

Cheers