Compressor won't turn off?

[zachattack721]

Has anyone else had this issue? I drive a 92 Sport, 4X4. I bought the vehicle knowing that the A/C didn't work, I checked under the hood and noticed that the compressor wasn't "plugged in": the small harness that plugs into the top of the compressor was unplugged and tucked underneath the 4.0 cover. I plugged it in, pumped some coolant into the system, and everything was hunky dory until my AC/heater fan went out a couple weeks ago. That's unrelated to the main reason behind the thread, but I'll take any advice concerning what to check concerning the fan.

Anyway, after the fan went out I noticed that cool air would seep into the cab while I was at speed, with the A/C turned off. While idling the compressor would engage for a couple of seconds then turn off for a few, rinse and repeat. I unplugged the harness again because I'm not sure the effect that an always-running compressor would have on the vehicle. If anyone out there has any ideas, I'm happy to hear them.

 

[Wolfie_85]

Are you sure you pushed the fan speed knob in to turn the compressor off? No orange light? It will stay on even with the fan turned to "off" if you don't push the knob to turn it off.

If you're up on that, your problem lies in the climate control unit itself, I'd bet. Easy to find at a salvage yard.

 

[arco777]

Check the owner's manual; on my non-AC version it specifically states you will still get some air coming through the vents with both the fan OFF and selector lever OFF - I believe you have to set the lever on DEFROST to block airflow.

Wolfie_85 is correct, check that your fan speed knob is not pushed in. Normally an orange light indicates the compressor is on. If that light is burned out and the knob is pushed in, it might not be obvious that the AC is still engaged.

 

[Bobmbx]

Sounds like the compressor is operating normally by cycling on and off.

For the blower, its most likely one of two things: the blower itself is bad, or the blower resistor is bad. If the blower only works on HIGH, then its the resistor. One way to check the blower is to apply 12 volts directly to the blower positive contact, and ground the negative side. If it runs you know its good.

Changing the blower or the resistor is fairly simple.