my 04 vent temp gets to 50 degrees on the road, sitting will drop down to 40. i have trace it to low pressure cutoff...idle all is well, soon as you increase rpms clutch kicks out due to pressure dropping. dealer replaced coil under dash (now has a rattle) but did not help the sutuation. i do a lot of start and stop driving and it just doesnt get cool enough for me.does ford offer different pressure switches? it has 48k so it is out of warranty.

 

A/C won't perform very well in high ambient temps in stop and go driving. There's little airflow over the condenser, it's just the nature of the beast. Has your dealer verified that the system's fully charged? Mine was undercharged by about 8 ounces from the factory, I swept and recharged it and it works alright now.

 

well i put more freon in before it went to dealer and no matter how much i put in ,the pressure would still get to the point of cutting out when accelerating the engine,cant remember exactly but i think it was running about 30lbe then increase engine speed to about 1500rpms pressure would drop to 25 and compressor would cut out. the other weird thing is the vent temp is coolest (40) when idling.soon as you start moving the comp cuts out and vent temp goes up to 50 degrees.can i get a different value of low pressure cut out?i read that some were adjustble, but didnt see any screw between prongs.i would only assume dealer would putthe right amount back in when they change evaporator.

 

Stop right there. Um, just how much is in there?

 

i put one can in and i still had the same problem,so i let some out till it was low then added some till it cooled like stock.....but then the dealer has handled it from there.

 

The system needs to be drained, swept and charged with the proper amount before going any further, IMO.

 

The older pressure switches were adjustable, un plug wiring connector and look in the base of the switch it will have a screwdriver slot for adjustment turn one turn at a time untill desired pressure is seen this may help if this is youre problem. you also could have a problem with the fixed-tube-orafice or screen.
If memory serves me right clockwise increases pressure.