Fiesta 2015 1.0 Ecoboost solved AC cooling problem

[Bazzaclark]

After a few days of complaints by wife that it was too hot in the car this summer, I saw that the AC clutch was jumping in-out every few seconds. Afetr an internet search I ordered a can of R134 refrigerant and a cheap nozzle and gauge from Amzon to top-up the system. I used the whole can, but was dissapointed when the system still did not blow cold. I took off the front (bumper) and checked the system for obvious leaks, and then cleaned the AC radiator fins - no change. Finally I did the AC compressor clutch check by shorting the terminals on R9 relay in the fuse box under hood to force the clutch 'engaged'. The system did 'try' to cool. I then reread instructions and saw that the refrigerant pressure at the LP top-up point was too HIGH (over 60psi). I simply let some out with the clutch engaged engine running and max AC, down to around 45psi. Hey presto, it seems the AC works again. Need to test it on a journey to make sure, but it seems that the refrigerant pressure was originally too LOW< then i made it too HIGH, and then back to 'just right'. Glad it was not bad sensors, switches, orifice, leaks , compressor etc. Hope it helps someone.

 

[Handy Andy]

Nice catch, for that pressurization, if too high - will blow out the needle valve used for the expansion and kill the AC - even damage the engine if ignored. Compressor kicking in and out - that action takes a lot out of the drive serpentine belt.