I posted this in the Super Duty forum with not much luck so I hope posting it here will help me. My A/C was blowing warm air so I purchased a can of A/C PRO at a local parts store a couple weeks ago. My system was so low the compressor would not come on. I put a 20oz can in and the compressor started working. I let the truck idle for the recommended fifteen minutes, the air was not so cold anymore, and the gauge was reading low. So, off I went to the parts store to buy another can. It is in the correct range on the gauge now. I was wondering how accurate the gauge was on this can so I had a friend hook up his professional A/C gauges and it was reading the same as the one on the can. I took the truck for an hour drive last weekend with the family to a lake for a picnic and noticed the A/C started blowing a bit warmer air, so I shut it off and rolled down the windows. I have noticed after all this my compressor does not cycle off and on, it just stays on even when the ambient temp is 65 degrees. I checked the pressure yesterday and it is holding in the correct range still. I am wondering about the air gap in the clutch so I borrowed my neighbor’s feeler gauges today and checked my air gap. It was about .037" so I removed the clutch and took out the only shim. Put it back together and it is .021" ran the truck and the clutch did not turn until I turned on the A/C, then it engaged. Hooked up my low pressure gauge and checked the pressure and it read 24 psi with the fan on low. The ambient temperature at this point is 70 degrees. I put a meat thermometer in the vent closest to the steering wheel and after just a couple minutes, it was reading 40 degrees. I turned the fan on high and noticed the pressure went to 35 psi and the temperature in the vent started to rise. I turned the fan back down to low and the pressure dropped back to 24 psi and the temperature went back down to 40 degrees. I noticed the clutch still is not cycling it just stays running. I left the gauge hooked up to see what the pressure was off and it read about 94 to 95 psi. Any ideas on what to do next? Thank you, Danny W.

 

So, what's the problem?

 

I am wondering why it is getting warm when I turn the fan up.

 

How warm?

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I talked to Ford today and for $135.00 they will hook it up and see whats doing. Thanks....