I just installed a flatbed on my truck (03' 2500 4x4) with 4 shiny new led lights. I cut the factor taillight plug off, used my test light to figure out which wire is which and hooked the lights up. The 3 wires that are coming from the light are white(ground), Black(tail light), and Red (brake/blinker). I hooked up the ground and tail light wires and everything is OK, but when I hooked up both the brake and blinker wires to the light and tested them the light flashed like a strobe light. Also, when the key is off and there is no juice going to the light 2 individual leds are dimmly shining and I have no idea why. I tap splices the brake/blinker wire to my trailer light plug and the lights work fine but the blinker blinks very fast and the "lamp out" lights stays on my dash. Any ideas or suggestions?

 

Also my back-up lights haven't worked for some time, is there a sensor somewhere that went out?

 

The LED's don't put enough load on the thermal flasher. Get an electronic flasher.