I cant remember the year but at work there is a older F550. I have messed with a lot of ac stuff and always figured it out but this one is a deal. I think it has always had the same problem but it will cool great setting then about 5 miles on the road the compressor clutch kicks out and will not work again till its parked . It has a new compressor, low presser switch and expansion valve. The pressers seem to be ok i wish i could leave the gauges on going down the road. Maybe its a wiring problem? The first shop i worked in had a guy and he was the only one that did ac work . Watching him try to fix some ac made me think i will never get into that .
The older Fords I have worked on had a pressure switch on the low pressure side and if the charge was low the extra cooling from the air movement through the condensed would lower the pressure enough to cause the system to cycle off for several minutes at a time. I'm not sure if Ford still has the switch on the low side. Are you sure there is the correct amount of refrigerant in the system?
I replaced the low side switch. Before it cycled a lot. I just got a high side switch I am going to try today. I think it has the correct amount of refrigerant.
I replaced the high side switch and it seems fixed . Before i would drive it 5 miles it cooled great then it would quiet and not work the 5 miles back to the shop. Today i drove it and it stayed working. They took and used it and said it worked. It sure acted funny.