I have compact unit in my truck,after switching trucks it started warming up slowly,it runs but only for short times,like 1 min or less. It now is only keeping it 50 deg even in freezer. I dont are if it runs all the time I think the controller is dead, can it be shorted out? Kindof broke right now. Has been a good running unit for a couple years even with all the bouncing. Thanks. Gary Martin