2002 ford mustang ac will not come on. Problem is intermittent. I have checked the low and high pressure switches and fuses. what else is there to check?

ac clutch is on the front of the ac compressor there should be one of the pulleys that looks different to all the others, why are you trying to find it, if it is noisy fair enough, but if it is not cutting in then connect a test light to the wire to it it should earth through the body of the compressor and gets power from the wire but if there is no power there may be an issue with low aircon gas or a hi/low pressure switch could be a fault (dont remove the switch if there is gas in the system) it could be something as simple as a fuse hope this helps
cheers paul

If the A/C compressor does not come on, the compressor clutch is not getting power or the freon level is too low. Reasons for no power include blown A/C fuse, bad switch on console, bad solenoid on compressor. I would check the fuse first. If that's ok, next check for power at the compressor with a test light or volt meter. Next, try to jump power to the solenoid to get it to pull in. Do yourself a favor, and get a schematic for the car. It will make it easier to trace out the wires and find the problem. You can check out repair manuals from the library and copy the schematic from the manual.

FIRST I CHECK ALL FUSES AND RELAY.TO BLOWER MOTOR IF IT STOP BLOWING.AND CHECK FUSE TO HVAC SWITCH CONTROL.AND CHECK FUSE / RELAY TO AC COMPRESSOR.IF FUSE / RELAY GOOD POWER GETTING TO AC COMPRESOR CLUTCH COIL AND LOW PRESSURE SIDE 28 PSI AND HIGH SIDE 200 PSI. CLUTCH COIL IS OPEN.IF REFRIGERANT LEVEL LOW YOU MAY NEED MORE REFRIGERANT.YOU NEED AT LEAST 28 PSI ON LOW SIDE AND 200 - 220 PSI ON HIGH SIDE.IF ALL IS GOOD STILL NO AC PROBLEM COULD BE A FAULTY AC CLUTCH CYCLING PRESSURE SWITCH.

Call your local Ford dealer, and ask, otherwise use the process of elimination??? easier to make the call...

Check fuse and also low pressure switch located in engine bay at the ac hose close to the wall passenger side. If low gas safety will not allow compressor to come on!.

Sounds Like The High Pressure Switch on The Air Drier On The Passenger Side Firewall Unplug The Connector From The Switch That Is In The Thing That Looks LIke A Cylinder They Are two Hoses Coming Out It Now That You Found It Take A paper Clip And Stick In Both Contacts On The Wire With Car Running And A/C On The Compressor Should Kick on At This Time If It Does You Know That The Compressor Is Good But I Would Not Leave It Plugged Up Like That For More Than A Few Minutes It Can Burn Up The Compressor If IT is Low On Gas It Will Not Kick on If You Know That It Still Is Full of Gas Then Your High Pressure Switch Is Bad I Would Recommend Making Sure Its Full Before Purchasing A Switch If You Change Switch It Just Unscrews out Counterclockwise

possibly low on freon thers a switch that will not let it engage if pressure is to low!!! hope this helps you!!!also check for 12v at compressor!!good luck!!!

You were close! Most Fords have a CCRM (Continuous Control Relay Module) thats on the passenger side fenderwell. It has 4 relays: one for the AC compressor cluth, one for the fuel pump, and two for the electric fan (high- and low-speed.) The AC is the one that fails the most. You can replace the CCRM by removing the intake air filter box and working through the fenderwell openings. If it gets to difficult you must remove the wheel and splash cover to replace it from the wheel opening.

I don't know about the part #. But the low pressure switch is on top of the accumulator, maybe the compressor is not cycling due to low refrigerant.If you are low on refrigerant the low pressure sensor will shut off the compressor.

check the low psi switch and the high psi switch both will be on the lines you will have to look for them not sure exactly where low side may be on the accumulator try jumping them with a paper clip and see what happenes watch the pressures on the system because if pressures are to high or low you could damage the compressor or blow lines if either switch is bad it will cause computer to cut out the a/c clutch let me know how you make out