just bought a 93 240 station wagon.
Unfortunately, the air conditioning isn't working so great. I do get a little bit of cold air, but not very cold, and seems to go in and out, and is no match for the nyc summer.

Reading other topics related to the A/C, I understand even less than when I started.

I bought one of those cheap recharge kits (link here: https://www.midwayautosupply.com/detailedpr...iption.asp?9851 ... realized too late I didn't need the retrofit part, as 93 volvo is already R-134a).

First, have no idea which is the low-side service port. Terrible instructions warned me against connecting the can to the high-side, but how I am I supposed to know if the service port I found (located right next to the refrigerant, labelled "R-134a") is the low-side service port?
I did though connect the gauge to this port without connecting the can, and turned on the blowers on high, and the gauge would jump between 20 and 40 psi. Would stay on 40 for about 3 seconds, then would hear a 'click', and it would jump down to 20.
this seems to maybe explain the problem of the air going from cold to no-cold, but have no idea what any of this means.

please tell me i can just empty one of these cans into the service port and I'll have cold air for the rest of my life without having to spend any more money.

does the "clicking" sound familiar to anyone? Is there anything I can do to fix it without being in danger of blowing myself up, or worse yet, blowing up my volvo?

thanks.

The clicking could be the clutch on the compressor disengaging. If it disengages too frequently this could mean your refrigeratnt is low.

I just go the A/C on my 87 working. I had a few different problems, but the final issue was the valve separating the hot & cold was not shutting the hot water off completely so I was constantly getting hot air. To prove this, I clamped the hot water hose go to the heater core off. Once I did this, the air was frigid. It might be worth a try if your sure that there is enough freon.