I have a 98 v70 non-turbo. Noticed the ac clicking on and off when driving and yesterday it stopped clicking on at all. I googled around and some people say that it just needs a charge. Got a 12 oz can of r134a and charged it. Had to jump the low pressure switch to get it to pull the r134a in.

After the charge, the ac then would cycle on and off every second or 2 when the car was not moving as was. I guessed that it needed another can? I don't think I emptied the can completely. Fog came out after i popped it and it felt like there was some liquid in it. I finished late so I decided to get a second 12 oz can in the AM.

When I shut off the car, I could hear a hissing noise coming from the air vents. I didn't listen at all the vents, but I could hear it coming out of the dash vent on the far passenger side.

I went to bed and when I tried turning on the ac in the AM, the compressor clutch would not engage.

I'm guessing that something under the dash has a major leak? is it common to hear a hissing noise after shutdown? Should I waste money getting another can or should I get a can with dye or sealant in it?

Got the car about 3 months and this is my first real fix ac has been blowing cold the whole time. Upgraded from a 94 945 turbo. So far things actually seem to be easier to work on than a 940. Cool beans.