I have an 18 lariat with stock leds and bliss. I have installed a tailgate lightbar on the truck and it does not work using the 4 pin plug to trailer hitch plug without causing issues. Anyways this is a good lightbar with a 5 year warranty not a cheap bar. It has been on for over a year now with no problems. Recently it started to cause my blinkers and left brake light to malfunction. I have light direct wired to left wire harness. It could be a short in the bar but it works perfectly fine. It is only affecting the stock lights. The wire connections were fine. I know these trucks are very finicky with electronics. My question is does anyone else have a tailgate lightbar installed on a 18 with the led tailights and if so how did you wire it. Want to use the lightbar but don't want to waste more money on bar if it's not going to work. Thanks

 

I have a light bar installed on my '15 w/ LEDs and the BLIS system. Direct connections to the left side harness for the GROUND, STOP, REVERSE, RUNNING and LEFT TURN SIGNAL, direct connection on the right side harness for the RIGHT TURN SIGNAL. Works fine and mine is a "cheap" one.
Double check all your connections especially the ground.

 

If it's a putco there is a special way to wire them to a Ford truck with Blis and LED tails. It has to have a jumper added under the dash to send power back to the bar or it WILL do some funky stuff (ask how I know this) The proper wiring can be downloaded from their site

 

I think I may give the putco bar a try. Thanks

 

I have Putco as well. A bit finicky to install but the instructions are clear and it works well. As per others' recommendations, I only used posi-lock connectors and covered each with liquid electrical tape to keep it sealed.