So I replaced my turn signal, side marker lights, and brake lights with LEDs and now they only work properly if the headlights/running lights are on. If they are off, i can put on either turn signal and all of lights blink very fast. Anyone have an idea of what could be wrong? Im guessing because of the can-bus system it isnt compatible with LEDS?

 

I think you need a flasher that works with LEDs. The LEDs don't provide enough resistance to trigger the flasher. If you google it there should be a ton of answers.

 

There is no flasher in the JK turn signal system.

A resistor in needed in the blinker circuit. I'm sure a JK-Forum search will bring up some information for you.