Low pressure switch failed

[Bitsyncmaster]

On that AC convert I just did, I discovered the low pressure switch was not turning the compressor off even when the low pressure was at 10 PSI.

I tried adjusting it up to two turns both ways and it never opens the circuit.

You can test the low pressure switch by running the cabin fan off or at fan speed #1. This pulls the low pressure side low because your not using all the AC cooling.

AutoZone did have a replacement low pressure switch for $11.99 + tax.
Their part number is MT0207

Marked on the switch is:
YL-1213
ON 3.1 kg/cm2
OFF 1.7 kg/cm2

[hmcelraft]

If you disconnect the switch the compressor turns off? If that is the case the suction line may be clogged. I put too much oil in once and I had the same issue until I discovered what I did. I thought the switch was bad until I put the gauges on and found I was pulling near zero lbs. on suction at the compressor and 35 lbs. on the accumulator with my gauge attached there. Oil was clogging up the line.

[Bitsyncmaster]

Yes when I pulled the connector off the switch, the compressor would not run. The new switch fixed the problem.

I also checked the bad switch with it removed and read about 5 ohms. It should be an open circuit under no pressure.