Did you unplug the connector from the BACK of the 7 pin/4 pin to see if you had power there? Someone already suggested that it may have come loose.

 

I'll check that tomorrow. I don't remember ever touching that but may never know.

 

Trailer Tow module is another possibility, it controls the turn/stop lights. The parking lights are controlled directly. Are your sure that's plugged in?

 

Where is the trailer tow module located? Is that a fuse in the engine bay or passenger side kick panel?

 

Are you getting the acknowledgment on the info display that the trailer has been connected when you connect the trailer? Have you checked the ground connection to the trailer frame for corrosion or looseness? Perhaps the truck has to sense a sufficient electrical load from the trailer in order to acknowledge the trailer connection and activate the trailer lights and back-up assist.

 

Just to avoid confusion, the 'trailer tow module' is called ITBC - Integrated Trailer Brake Controller.

It will not light brake/turn on either of the connectors if it thinks there is no trailer attached.

 

I believe its under the dash close to where the switch is and that is what does control the brake/turn signals on a trailer.

 

your sure ...there is a brake control on the dash and a module to the left of the brake pedal..

 

Hope these uploaded

 

here's page one