I agree with Curly. R-134a systems are even less forgiving of blind
additions of refrigerant than the old R-12 systems were. At least on those
you often had a sight glass, and failing that a set of guages gave you all
the info you needed to get in the ballpark. Not taking in the refrigerant
makes me think the compressor isn't engaging... which is in itself a symptom
of all sorts of A/C possible problems.

Count your blessings that it didn't take on more charge. If your charge was
very low (especially in a car that is only 10 years old) you have a leak
that needs to be repaired before your A/C will give you decent service.

Anyway, I've learned my lesson. In the days of R-12 I'd do it all myself,
but R-134a is just too spooky for my talents. I will do the troubleshooting
to determine if the problem points to the "charge" (the amount of
refrigerant) and if that's where the problem is I take it to a pro. It's
cheaper in the long run. An A/C professional will be able to find the
problem very quickly even if it isn't the charge, but when I have more time
than money I at least like to hunt down the device responsible for the A/C
not working.

Mike

Hi, I have a 97 Civic EX.  Recently my A/C stopped pumping out cold air, it
was just hot air as a matter of fact.  I went to Target and bought a can of
Artic Ice R-134 coolant that had the hose and gauge already built in.  I
followed instructions exactly.  Hooked it up to the low side line, squeezed
the trigger, and then nothing.  My car isn't sucking this stuff in.  What do
I need to do?  My step-dad is a mechanic and he said I might have to do
something with the receiver/drier, but I have no idea where that is or what
to do with it.