Auto Air Conditioning & Heater Repair: a.c.compresor dont clutch, chevy astro, pressure switch

Question
I,have a 99 chevy astro and all of the sudden the a.c.stop working and notice that the compressor is not clutching.I checked the fuse and the relay at the engine, and the one under the dash and they're OK is there any others.it only blows air,I jumped and did engage but no cold air still,I use my tester in the plug behind the clutch and it was no power so I suspect of that wire.can you help me and tell me what else can I do to fix my problem I am a DYS and I will thank u for all your help

Answer
Hello Mario
We are a UK company and have no experience of you vehicle sorry. If you have jumped it and it works then there is a problem with the feed to the compressor.

You will need to trace that feed back to the switch on the dashboard. It depends where the feed goes from there, at some point it will pass into a high pressure switch.
If this is not activating the compressor won't kick in.
One of the reasons it won't kick is is that there could be no gas in the system
Has this been checked and has it got enough gas ?