air condition not working

1998 JEEP GRAND CHEROKEE LAREDO
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MECARCHASER
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The air compressor keeps cutting in and out when fan is on. when I put the air con on it just cuts in and out as well. Also the 2 pipe get real cold. any ideas? cheers
Aug 17, 2010 at 5:34 AM
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KHLOW2008
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Hi mecarchaser,

Does the compressor cut in and out with any or specific blower fan speed mode with A/C switch turned off? Was any repairs carried out prior to this occurring?
Aug 17, 2010 at 9:36 AM
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MECARCHASER
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hi,
I don't know what this means HVAC system? so I don't know if it's manual or auto

the compressor DOES cut in and out with any fan speed mode with A/C switch turned off?

I haven't had the car long so I don't know if it had repairs done

I took the air con relay out and know have more power it was like cutting the power down with air con cutting in and out

also when you put the air con on it still just cuts in and out

thanks
Aug 18, 2010 at 8:04 AM
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KHLOW2008
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HVAC is an acronym that stands for the closely related functions of "Heating, Ventilating, and Air Conditioning" First diagram shows an automatic HVAC control panel.


https://www.2carpros.com/forum/automotive_pictures/192750_HVACControlPanelAuto98CherokeeLaredoFig01_3.jpg


https://www.2carpros.com/forum/automotive_pictures/192750_HVACControlPanelManual98CherokeeLaredoFig01_1.jpg

Something has caused the compressor to come on when the blower motor is turned on. What is the engine capacity for your vehicle?
Aug 18, 2010 at 9:26 AM
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MECARCHASER
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Mine is NOT automatic HVAC we call automatic HVAC "Climate Control". and the motor is a 6 cylinder 4ltr. What is a blower motor? is that the heater fan? thanks
Aug 19, 2010 at 5:06 AM
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KHLOW2008
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Blower motor is the heater fan.

Did you try swapping the A/C clutch relay?

The A/C compressor clutch relay is grounded by the PCM and it could possibly be faulty. Check all ground circuits for proper and clean conditions.

Does the A/C compressor kicks in and out when the blower is not turned on?
Aug 19, 2010 at 7:02 AM
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MECARCHASER
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thanks
I did swap the relays still the same '
if you turn the blower fan off it doesn't cut in out
but than I can't use my heater.

some one else said check the earth(ground) leads

how do I check them they look alright to me
can I use a multimeter to check it?
cheers
Aug 20, 2010 at 6:43 AM
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KHLOW2008
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To check for a bad gound, the easiest way is to use an ohmmeter. Push probe to a well grounded location and use the other probe on any ground wire that you wish to test. Anything more than 1 ohm should be cleaned and retightened.

It might not be a ground circuit connection but a faulty Power Control Module or a leaking vacmun line.

The A/C compressor relay is activated by the PCM and if it is kicking n and out, the PCM is either faulty or it is getting the wrong signal from somewhere.

The heater fan should not turn the compressor on unless it is shorted to the circuit.

Here is a wiring schematic. Note the location of the ground circuits that should be checked. Check out the diagrams (Below). Please let us know what you find.
Aug 20, 2010 at 7:26 AM
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ZANYJB
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I had to replace the AC compressor cost $234.00 my friend helped me fix it.
Nov 12, 2019 at 3:14 PM