Compressor clutch engages with the a/c on and disengages with the a/c off but with the a/c on the clutch never disengages. Figured it was the cycling switch on the accumulator because when I unplugged the connector with the a/c on the clutch disengages. Got a new one, same problem. Got another one, same problem. My radiator fan works fine but my car seems to very very slowly overheat with the a/c on and I remember my clutch used to cycle every 8-12 seconds or so at idle with max a/c. What do ya'll think is going on? Thanks.

Is your A/C charged?

It blows cold. I did a 134 retrofit about a year ago and everything's been fine up until now. Wouldn't a low charge make the clutch cycle more? Would new cycling switches be made for the original r12 system and maybe need to be adjusted with the screw inside it? Does the switch close the circuit when the pressure gets too high or low? This same problem is happening with my 94 blazer. Very peculiar. Thanks again.

Well it is hot in TX at this time of year, so it would cycle less. But I'm going to guess that when your system got converted to R134a, they adjusted the low pressure switch too low. It would be lower than stock what with 134a being less efficient than R12 and of course being TX where people live by air conditioning, I could see the tech turning it down a bit extra.

If you don't have pressure gauges, I'd ask a shop to hook up a set and see where the psi figures are. My system turns on at 47 psi and off at 26 psi (never been adjusted from the factory)

I put a factory R134a cycling switch on my van. On @ 35 PSI and off @ 18 PSI. Blows 45* on high blower.