I think I've overcharged my a.c. system.
About two months ago I charged it with a do it yourself can from an auto parts place. Large blue can don't remember brand. Once on highway cooled great. But in slow downtown traffic didn't cool well. So today I decided to put more freon in to see if that would help. Nope, now it's not cooling at all and my compressor is making a strange sound. What can I do to fix it? I don't want to damage anything, so I won't run it anymore. What would be the proper way to discharge some of the freon?
94 4.0 ranger

 

Proper way is to take it to a shop that has a recovery system.

Harbor freight has a gauge set for $55, if you have some friends that also have AC in their vehicles it is worth it to get an AC gauge set.
AC Gauges - Save on this AC Manifold Gauge Set

Not sure on the quality of the above, they usually cost $200-$300 for a set like that.