OK, quick "what to look for" on the gauges. All you need to hook up is the low side on the gauges to the low side port. Make sure the other side is closed. You can also just get one of those cans with the gauge on it if you want- just use the gauge and don't penetrate the can. I'm just a little scared of those because most of them come with stop leak. I also suggest that you do this in the shade.
Ok, now that it's hooked up, turn the engine on, turn the AC on Max/recirc with the temp all the way down. Watch the gauge. If it's low on charge, then the gauge will drop to 20 psi, and then the compressor will cut off and it will rise back up to 100 or whatever it was previously.
If that's the case, then you can remove the hose, penetrate the can, and go through the same motions to add some refrigerant. I would add refrigerant until the low side pressure was around 36 -38, then rev the engine to about 3k rpm, and see what the pressure drops to. You don't really want it to drop below 32 or the evap could end up with ice on it.
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Originally Posted by the user formerly known as ZX3_Chick
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