[Robznob11]

The problem is that led flashers (digital )a re polarity sensitive . If you swap the two wires in the flasher it would work with any digital flasher. If you look the prongs are marked . The only other possible problem is that the led tails could be wired backwards for your truck.i have ran across 3 trucks so far where the wires for park and brake/turn are reversed, so when you plug the 1157 in they seem to blink fine until you turn on the lights. Thats because the dim side is blinking. When you turn on the parks the bright side lights up and you no longer can see the blink. One other issue i have ran into with full leds is when someone uses switch back leds in the front. The internal circuitry of the switch back will back feed with the white parking lights on causint the yellow turn to light up but no blink. When you turn the white park light off you kill the back feed and you then have enough load to make the flasher blink. If you ever think you have this issue then add a load resistor to check if it works. If so that is the problem. In this case you can either run a load resistor, or not run switch backs. But with all leds your first check is the flasher polarity. If it is reversed you may have enoung load to flash until you turn on the park circuit. I have seen it happen more than once. Also alot of flashers claim no load ,but they should be labled low load.....