04 Subaru A/C not cooling
My 2004 Forester X25 A/C has lost its cooling this spring. It is my wife's car so I can't say she was good about running the A/C for a few minutes each month during the winter.
On first use today she said it isn't working. I checked and found the following:
1) no cooling
2) fuse 15 amp looks good, checked okay with ohm meter (number 17 in the fuse box behind the coin drawer - left hand low behind dashboard).
3) compressor and belt turning/engaged, but I can not see or hear the compressor clutch act.
4) further study of the Haynes repair manual I see an additional fuse associated with the A/C and it provides the current, via a relay, to the compressor clutch. This fuse is located more under the dash, not easy to check... so I haven't directly checked the fuse.
5) I also see in the Haynes manual a low pressure switch which will prevent the compressor clutch from engaging if the pressure is too low.
6) The A/C Relay is in a fuse box in the engine compartment and the relay looks like a plug in....but it didn't come out when I tugged with my fingers. Access to the four terminals to the relay would provide critical test information. Should I use pliers to remove the relay? Some plastic here.
Last year or the year before I added one can of refrigerant and achieved a significant improvement in cooling. That time the cooling was working, it just wasn't cold enough to be right. This year I can not feel any cooling with my hand.
I am considering just adding a can of refrigerant and see what happens-I have one can on hand anyway. I have never used a pressure gauge, just add one small can. This approached worked in the past on the Forester and has worked on other previous cars, a Mazda comes to mind.
Can one add refrigerant if the pressure in the system is so low that the low pressure switch is preventing the clutch from engaging? Or is the a catch22?