I'm new so bear with me please. The Tow/ Haul feature seems to only work when the unit is cold. Below 50 degrees ambient temp. First start in morning it works fine until I turn the truck off then will not come on again until the truck sits long enough to totally cool down. If the air temp is above 50 in the morning it will not work at all. All I have done so far is check the fuse, remove covers and check the switch wiring for cracks or open and ohm the switch. All checked good. I'm just wondering if anyone has experienced something similar. Thanks in advance. Ed.