When my climate controls are left on the hot side for the first half of the day but I now need the a/c for the other half of the day, so I turn the climate control all the way over to cold then I turn on the a/c but it never gets cold. It just keeps blowing hot air with the compressor on. I have to turn off the truck for 5 to 10mins start it back up, then it will start blowing cold air.