'91 V6 3.1 liter Firebird -- having A/C issues.

It was blowing outside air temp (hot today!), hooked it up, gauge was reading slightly low so I topped it off. No change. I don't hear the compressor kicking on at all. I had the same problem with my last car, which I topped off and swapped out the relay with no luck.

Ideas? Thanks!

 

ideas, here are a couple, but not a gaurentees.

The compressor might have seized up.

Dont just top of the freon, replace it, particles will like metal shroudings will damage the compressor and clog up the filters that are in the lines

 

if your compressor is not cycling on then you wont be able to get a proper reading on the gauges. jumper the electrical connector that is located on the receiver/drier, this will force your compressor to cycle on, then get the readings on the gauge. 30-40 low side is were you want it while car is at idle. high side pressure doesn't really matter at this point.

if your compressor does not cycle on when you jumper the connector, more than likely your compressor is bad, check for continuity through all the wires. if it does cycle on, and your readings are correct 30-40 then your low pressure switch is bad, replace it.