The car does not come with towing package. Bought and installed 3 relays; 2 under the hood, one in the back. I connected hard wired TOW READY 20137 to the trucks' wiring system, checked voltage, nothing. Checked relays under the hood and and the back by the rear light, I could hear the clicking from them. Do I need to connect under dash brake controller too in order the wiring to active the wiring system ? Any idea why this is happening

 

you need to test with the trailer hooked up as the ground is through the ball, or you can run a ground wire.

 

Thanks I will try that