Question1998 ford escort 4 cylinder-we were sitting in line to get something to eat and my ac just quit working.there is plenty of freon and i checked the fuse,all okay.the clutch does not engage.can the high or low pressure switch cause this to happen?there was not any kind of noise before it quit.
AnswerBruce,
Yes, both the high and the low pressure switch can cause the a/c clutch to disengage. They are vital safety components that protect your compressor and other system components from extensive and costly damage.
It just quit out of the blue? Natuurally the first thing I would check is the fuse, but you have done that and it checked good correct? And your refrigerant charge is correct? Hmmm...
I am looking at your wiring diagram now...
The next check I would make is your compressor clutch relay. This sends power to your clutch when its coil is energized. Your clutch relay is located in your underhood relay box. If you disconnect the relay, either on the side or looking at the prongs, you should see them numbered. Find contacts 22 and 16. Then identify which terminals in the relay plug these connect to. With a small insulated wire, key in run position (engine on or off) and the a/c switch on, jump these terminals in the plug. You should hear your clutch "snap"
If you do, the relay is bad and needs to be replaced. If you do not, let me know, and I will walk you through the rest of the wiring checks. In order to do the future checks, you will need a multimeter or a test light, though. But, I believe that you will find this relay to be bad, it is a common fault (more common than high and low pressure switches) and will cause your system to act as described.
Thank you for the question, I hope I was of some assistance. If so, please remember to rate this answer. If I can do anything further during this process or in the future, do not hesitate to ask. Thank you again and good luck in everything.
