I bought one of those little AC recharge kit things since my 97 LX was taking a while to cool down and then wasn't all that cool anyways. It was an all-in-one thing with a hose attached to the bottle already, and a plastic press-down release valve.
I had the car running, the AC on full with a couple of doors open to keep the compressor running (error there?). I connected the bottle to the low side valve next to the battery and gave it a few additions. Sometimes, a fog would come out of the top of the bottle underneath the button, making me think somehow the refrigerant was backing out of the system or something. Eventually, the condensor and cooling fans starting clicking on and off like the system was almost empty or something. Now it doesn't really cool that much and the condensor seems to click on/off more than it used to. Did the system somehow discharge, or did I overcharge it and now the compressor has too much to work against? Or, do I have to bridge some switch somewhere to ensure the compressor keeps running and do it again?

 

you really need to know the high and low side pressures to make decisions about the A/C charge.

 

Does Auto Zone or some place lend out a gauge that would work, or is there some type from Lowes I could buy and use once?

I've noticed that the compressor doesn't seem to be putting nearly as much of a load on the engine now. I used to have my dash vibrate quite a bit, now the RPM dips a little but with less drama in the rest of the car (this is at idle).

 

actually if he found the high side the bottle would have blew up in his face! the problem here is not knowing how much R134a is already in the system and just putting more because it's not cool enough unlike the old R12 systems that had a sight glass that had bubbles when low and clear when full but R134a systems theres less room for error. my advice take it to a a/c shop to remove the freon and put back the correct amount as there is way too much in the system now and the compressor is having a hard time with and tripping the high pressure safety switch.