I had a A/C clutch failure on my four year old Four Seasons A/C Compressor. I thought that was a premature failure. Long story short, I troubleshot it down to too low a voltage at the clutch. It was hovering around 5.5 volts and should be 10V or above. So it was picking but slipping and heated up - then failure. After pouring through the electrical schematics for the Delanair, I found that the RANCOR switch thermostat is in series with the clutch and full voltage/current runs through that switch. That switch is a normally closed and opens if and when the evaporator freezes-up below 36 degrees. The switch is located on the right side of the Delanair unit and has a long skinny probe that inserts into the housing. It's very easy to remove the entire switch; it's held on with two very small screws to a bracket. Then the probe just pulls out from the unit. Don't be afraid to pull it out. It just slips out. I then disassembled the RANCOR switch to find it has two contact points that were very dirty and burnt. I burnished the contacts and reassembled it back together. I just reinstalled a new Four Seasons A/C Compressor, as that's the recommended thing to do. As a burnt clutch overheats and may compromise the forward end of the compressor unit. Yes, I could have replaced just the clutch, and that's what I was going to do. But the clutch was $136, and a whole new compressor with the clutch was $286. I'm to the point in my life that I didn't want to have to do this job again, so I sprung for the whole magilla. When I put everything back together, the clutch is now making the resounding CLICK sound it should be making. So I suspect this is a problem I had from day one, four years ago when I installed the first Four Seasons Compressor. When will I ever learn to do the job right the first time!!!!!

 

excellent Bill !