Compressor just stopped

[BenHolliday]

The other day I turned off my AC so that I could hear a call better and when I went to turn it back on it was just blowing hot air. Prior to it stopping my AC was super cold and has never had an issue.

Compressor will not even try to engage, checked all fuses and relay. I can find nothing wrong. Is there a diagnostic sequence I can use to trouble shoot it. I've looked all over the site but cannot find a "How To"

98 Explorer, 4.0 Automatic

Thanks for any help provided

 

[Fiveologyjay]

I've had an issue with mine doing that. I'm not sure why but simply revving the engine engages it and it starts blowing cold again.

 

[BrooklynBay]

Check to see if you're low on freon. If the compressor is running, and it's blowing hot air, then check the blend door actuator.

 

[gbissi]

You can find the 2 pin a/c cycling switch, usually on the receive/dryer bottle and disconnect the connector and jumper the pins in the connector. That should make the compressor come on. If it does, then maybe you have a bad cycling pressure switch.
The way it works is the switch monitors low side suction pressure and engages the compressor to allow high pressure liquid Freon to spray through the fixed orifice. As the Freon evaporates in the evaporator in the truck, it absorbs heat and takes it to the condenser as a heated vapor. You don't want the evaporator to go below about 35 degrees F because the moisture will freeze on the outside of the evaporator and then you will get no air flow out of the vents.
So, the cycling switch makes the compressor go on and off as needed to maintain the proper low side pressure.
The cycling switch is in series with the a/c high pressure cut-off switch (near the compressor) that cuts off the compressor when the high side pressure goes above about 425 psi. That can happen in 90 degree plus temps when the high speed cooling fan motor is not working right. So, you may need to bypass that as a test to see if it failed completely.

Here is the basic system:
A/C System
The A/C refrigerant system is a clutch cycling orifice tube type. The system components are:

A/C compressor (19703).
A/C clutch (2884).
A/C condenser core (19712).
A/C evaporator core (19860).
suction accumulator/drier (19C836).
connecting refrigerant lines.
The refrigeration system operation is controlled by the:

A/C evaporator core orifice (19D990).
A/C cycling switch (19E561).
A/C compressor pressure relief valve (19D644).
A/C pressure cut-off switch (19D594).
The refrigerant system incorporates an A/C compressor controlled by an A/C cycling switch.

The A/C cycling switch senses A/C evaporator core pressure to control A/C compressor operation.

An A/C compressor pressure relief valve is installed in the A/C manifold and tube (19D734) to protect the refrigerant system against excessively high refrigerant pressures.

An A/C evaporator core orifice is installed in the condenser to evaporator tube (19835) to meter the liquid refrigerant into the A/C evaporator core.


Gerry

 

[Maniak]

Another possibility is the air gap on the a/c clutch.

Our '06 mustang was randomly turning off the A/C.. It seemed to do it more while getting off the freeway..

It finally did it when I was at the house and It didn't turn on when I put 12v and ground right to the a/c clutch coil so I knew the issue was there..

I shut off the car, checked the a/c clutch gap and found it was double what it should have been.. It is simple to change the gap on the a/c clutch.. If you don't have multiple shims in there you can buy a set from the auto parts store so you can mix/match to get the right gap (I can't remember the correct gap)..

~Mark