LarryDel wrote:
I did not try increasing the gain as it was set at 2.0 which is more than enough to work. Again, what caused my truck brakes to fail? My truck brakes work fine as soon as I disconnect the trailer. Never had this problem before in 10 years of towing.
2.0...out of 10.0? It may be that they work but barely. How strong is the pull if you just activate the trailer brakes manually?
Add in a loose or corroded connection and you could see a sudden reduction in braking from the trailer brakes. Now the truck brakes are asked to cover both truck & trailer and truck brakes may overheat.
Of course, this is just a guess as it's not clear from your description and there is no direct interaction between the trailer brake controller and the truck brakes.