well still working on this. I want to do as much trouble shooting as i can before resorting to taking my vehicle to the shop.
I am no pro but really just trying to figure as much as i can about my own vehicle. I've done my research and found out a few things. About the AC, I was always under the assumption that any car ac routinely needs an ac charge because after time the refrigerant just gets used. From what I understand now, a vehicle AC system is supposed to be always sealed. The refrigerant can be used as long as it does not escape through a leak. So a vehicle only needs a recharge if there's a leak in the system.
I was hoping that my issue could simply be a matter of buying a DIY can of refrigerant and filling my ac up. Evidently it is not so simple. Rather there will have to be pressure testing with proper gauges and troubleshooting where the leak is, then repairing wherever it's leaking. Only then could it be refilled, and which is a very careful procedure to avoid overfilling which could damage the compressor. And there's the DIY refill cans with leak sealants added which is kind of a gamble because these sealants can also clog the system and do more harm than good.
On top of that the DIY refill kits, according the directions I've seen, require that the fans and compressor are already running, which in my case they're not. Some folks hook the compressor up to the battery directly but this they say can damage the compressor if it's engaged without adequate oil, which it likely is when its on low pressure.
A vehicle like mine where the fans and compressor aren't running when the AC is turned on could either have a refrigerant leak somewhere in the system (could be leaking from several parts), a bad compressor (or a bad clutch), or a bad electrical connection (bad low pressure switch, connectors, fuses, relays). At least a dozen different things to check.
Today I got some aligator clips for my multimeter probes and tested the voltage at the compressor again, this time by sticking a paper clip in one side (did alot of digging before i learned that trick). Again I am getting around .14 volts. So I am sure theres no power there. I found these videos here this guy does a nice job step by step showing how to test every point in the electrical system, which is like a dozen check points itself.
https://www.youtube.com/watch?v=PMM80xlon3U&spfreload=1
https://www.youtube.com/watch?v=T3o1l4r_ERE
Looking forward to updating this fix to as not to keep folks left hanging who are searching for the answer on how to fix their chevy venture. It's just wonderful when folks open a thread, get feedback, and then never follow up with a conclusion to tell what the heck ever happened. Most of the threads on these forums are like that, just a dead end with no solution.