I have an mt-755 that I can't get the ac to work. We hooked the gauges up to it and on a hot day the high pressure side read around 110. But when the the tractor fan kicks on the pressure shoots up really high, but only when the fan runs. There are no fault code for the ac system. And there is enough freon in the system. Can I put an electric fan on it or is there a way to put a different engine fan that runs all the time? What have you guys done?