My brother has this tractor with a cab--2004(?) model. The air conditioner is flaky. He replaced the thermostat on the control panel and it worked for a short while. I checked it this weekend and found that the on/off part of the switch does turn voltage on and off and that the thermostat voltage varied as to where the **** was in the rotation. I also found that there is not any voltage to the pressure switch just before the compressor clutch. Beyond this, I am in bad need of a wiring diagram for this tractor. The wires off this thermostat control switch go over into the right side of the headliner to who knows what. Can anyone please help?? Thanks