Anyone know Jeep A/C?

[KELLY88]

My friend has a 2002 Jeep Liberty with a 3.6L V6. Well the A/C isn't working. It just blows hot air. I have an A/C pressure gauge and the freon checked out fine, the A/C clutch fuses are fine but the clutch still doesn't seem to engage. Not sure if it's relevant but the blower only works with the dial in the number 3 position; 1,2 and 4 just don't do anything. Anyone have any ideas?

 

[Earl43P]

Sure.

Fan speeds are controlled by a resistor block, virtually the same as your Ranger. Although High speed usually always works, as it's the dead short (no resistor).

I can't count how many cycling switches I've replaced on Mopars through the years. Simple enough to check, either read continuity through the switch or simply jumper the plug and see if the clutch engages. Power to the clutch HAS to run through the cycling switch (sometimes called the low pressure switch) so that when the refrigerant is low, the compressor won't come on.

Newer systems sometimes have a dual purpose cycling switch. It'll open for low pressure AND high pressure. Those have more than two wires, so you'll be able to tell. Either way, they are cheap and replaceable without leaking out the refrigerant.

 

[KELLY88]

Thanks. Any idea where the resistor block might be? We don't have a manual to work with here. Also is the cycling switch the plug on top of the A/C compressor?

 

[Earl43P]

LP Cycling switch should by located with the receiver/dryer, closer to the firewall. If you have a switch on the compressor, it is likely the High pressure switch and the low pressure switch is on/near the receiver/dryer.


Resistor block should be close to the fan blower, in its airstream (for cooling those resistor coils). So, near the blower, on the same plenum.

 

[KELLY88]

Thanks much. I'll check it out and see what I can find.