I would set the fans to run on high whenever the compressor is on, this is standard configuration on a lot of cars. Most of the R4 compressors have a spot to add a high pressure switch, I believe the default is to plug the port with a round metal plug retained by a snap ring. 80s g-body cars used the high pressure switch, IIRC it's normally closed and opens when pressure gets over 300+ psi. You can use the high pressure switch to ground the compressor clutch, that way if the pressure gets too high the clutch disengages. With both fans on, pressure at the high side should be around 230 psi on the high side at 85 degrees ambient. 35 on the low side should be about right. Again, you need to have airflow through the condenser, or the pressure readings will be useless. You may need to adjust the system pressure, but getting air through the condenser should be the priority.
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