Automotive Air Conditioning Information Forum

JohnHere wrote: ↑Thu Jun 06, 2024 10:49 am If the low-side running PSI is approximately in the mid-20s to mid-30s, then the pressure switch on the accumulator should be "closed," or infinite ohms on a multimeter, which would cause the compressor to engage. If a correctly functioning pressure switch senses abnormally low or high pressure, it would "open," disengaging the compressor. So the zero ohms reading that you tested means the switch is "open."

philipk1965 wrote: ↑Wed Jun 12, 2024 5:56 am UPDATE....
I put in 2 can of freon, pressures good L 32 H 133.
Works great now, Ice cold!

Cusser wrote: ↑Wed Jun 12, 2024 6:51 am JohnHere wrote: ↑Thu Jun 06, 2024 1:49 pm
If the low-side running PSI is approximately in the mid-20s to mid-30s, then the pressure switch on the accumulator should be "closed," or infinite ohms on a multimeter, which would cause the compressor to engage. If a correctly functioning pressure switch senses abnormally low or high pressure, it would "open," disengaging the compressor. So the zero ohms reading that you tested means the switch is "open."
I think JohnHere mixed this up.
"Closed" would be continuity or very few ohms resistance, likely less than 1 ohm.
"Open" would be infinite resistance, no continuity.