Here's a crazy thought I had. Could I trick the truck into thinking there's a trailer connected? I could plug in a spare 7 pin plug and only use the ground wire and blue brake wire. I would wire these to a normal spare tail light that I could lay in the bed of the truck. If I press the brake pedal, would the spair light illuminate according to how hard I press the brake? If it were to work, the truck would think a trailer is connected and I could drive it this way a few days and see if I get the "check trailer wiring " message. If I did, I would think something in the truck is causing the problem. If not, I would think the problem is in the trailer. Would this work?
