A/C clutch won't kick on

[ronmexico]

hey guys my A/C clutch won't kick on. Has adequate pressure but won't turn when i turn on a/c. Could it be the relay? anyone else have this problem or fixed it before?

thanks for any help guys

1997 gc laredo
4.0 4wd

[ronmexico]

a little more info for ya. compressor sounds ok when i spin the clutch. also there is a pulley that squeaks, could be the a/c pulley, i don't know, could this be the problem?

[dksob81]

Disconnect the low side switch from the DRIER (canister next to the coolant overflow bottle, has 2 tubes coming out of the top of it and an electrical connector), using a wire 9small 16 guage or smaller) stick it in the terminals of the wire, the clutches should kick on and stay engaged, if this works then the LOW-SIDE pressure switch on the drier is bad.

[cajunchopper]

Can the switch be adjusted? And if the switch is good, then what?

[Bob D.]

Originally Posted by cajunchopper

Can the switch be adjusted? And if the switch is good, then what?

The switch is not adjustable, nor should it be... it's very important that the compressor shut off at the proper times.
If the switch is good it may just be low or out of refrigerant. On a '97 it could be other things as well.

Jumping the pressure switch - make sure it's only briefly, one or two seconds. If the refrigerant has leaked out, running the compressor could damage it.
If the compressor does not engage, replace the switch.
If the compressor engages, the best thing to do is buy a basic two gauge set, high and low side, or at minimum a low side gauge or a can of R-134a with a low side gauge on it if you're going to DIY the a/c.
Take a static reading. If the static pressure is low, start the engine and add refrigerant. The compressor should start to cycle on and off - if it does not start to engage, briefly jump the low pressure cut off switch on and off and watch the gauge, the pressure should go up and the compressor should start to stay on by itself. Charge the system to specs.