[electro]

The cycle switch must be in the closed position for the compressor to engage.
Generally as the pressure is falling, the switch will open at 28psi. If the pressure is rising the switch will close at 31. Commonly the spec is 28-31psi. It is easier to bypass the cycle switch than it is to test it. If the A/C works when switch is bypassed, you have a bad switch, and need to replace it. The cycle switch is almost always on or near the accumulator (large can).

To jump switch, remove the 2 wire connector, insert wire jumper, start vehicle and turn A/C on and blower on highest speed.

If compressor engages and systems cools, the switch is most likely bad.

If the compressor engages but the system does not cool, you should suspect that you have no refrigerant. Do not leave the wire attached to the connector. You need the protection of a properly functioning switch.
The low side should be about 30psi at idle, blower on high, on a warm day.

 

[marel]

The cycle switch must be in the closed position for the compressor to engage.
Generally as the pressure is falling, the switch will open at 28psi. If the pressure is rising the switch will close at 31. Commonly the spec is 28-31psi. It is easier to bypass the cycle switch than it is to test it. If the A/C works when switch is bypassed, you have a bad switch, and need to replace it. The cycle switch is almost always on or near the accumulator (large can).

To jump switch, remove the 2 wire connector, insert wire jumper, start vehicle and turn A/C on and blower on highest speed.

If compressor engages and systems cools, the switch is most likely bad.

If the compressor engages but the system does not cool, you should suspect that you have no refrigerant. Do not leave the wire attached to the connector. You need the protection of a properly functioning switch.
The low side should be about 30psi at idle, blower on high, on a warm day.

the shop where I took my truck recharged the a/c but I was told that with the leak it probably wouldn't last long. about the clutch..I could always hear it engaging and disengaging.. now nothing.

 

[phillip Roderick]

The cycle switch must be in the closed position for the compressor to engage.
Generally as the pressure is falling, the switch will open at 28psi. If the pressure is rising the switch will close at 31. Commonly the spec is 28-31psi. It is easier to bypass the cycle switch than it is to test it. If the A/C works when switch is bypassed, you have a bad switch, and need to replace it. The cycle switch is almost always on or near the accumulator (large can).

To jump switch, remove the 2 wire connector, insert wire jumper, start vehicle and turn A/C on and blower on highest speed.

If compressor engages and systems cools, the switch is most likely bad.

If the compressor engages but the system does not cool, you should suspect that you have no refrigerant. Do not leave the wire attached to the connector. You need the protection of a properly functioning switch.
The low side should be about 30psi at idle, blower on high, on a warm day.

what if you bypass switch, the a/c works, then you replace the switch and have the same problem?