Lots of AC issues... Wont cycle?
 

Well, it seemed i had no ac when i got the vehicle,.

brought it to shop, paid 140 for him to fill it up with the mac tool machine that did like 1 hour worth of testing, vacuuming, oiling whatever the hell it did lol.. well worked for a couple weeks. HOT air again. K. Brought it back today, he filled it up, free, this time with dye cause he couldnt find the leak even while pumping it up with the sniffer. So now it has dye in it. Well i went and got it, drove home with no "pull or laggg in the throttle" so clutch wasnt engaging, was blowing room temperature air. Fk.... Got home, figured maybe clutch **** out, jumped clutch with paper clip. shut off the ac when clutch engaged, called him back, hes like bring it in tomorrow morning again (today was free, so is tomorrow) so i went out, plugged the low pressure? switch into that sphere thing on left hand side of the motor,and i went in and in it (+42c outside today hot as balls) turned truck on, ac came on! blowing cold! But no cycle like it ysed too? It ran full balls out for like 15 mins without cycle?

Did i **** something up jumping it?
Is it just to hot to cycle?
To much or too little freon to cycle?
why did it kick on after i jumped it, shut vehicle off, and re plugged in the switch, then turned truck and ac back on? Bad connection?

Im about ready to sell this hunk of junk....

Oh, and nowwhen i shut the vehicle off, that silver sphere thing (drier??) rush outside, i can here a slight hiss for a few seconds???

Yes, the "silver sphere thing" is your accumulator, and the low pressure switch is plugged into it. As refrigerant moves through your system, it changes state from high pressure vapor to high pressure liquid to low pressure liquid to low pressure vapor. It's all supposed to be vapor by the time it gets to the accumulator, but sometimes it isn't 100%. The accumulator contains a desiccant to trap moisture and ensure that only vaporized refrigerant continues to the compressor.
The heat will have an effect on your AC system... the refrigerant gets heated and exchanges that heat to the ambient air which flows through the condenser coil (or fins). This process counts on a substantial temperature difference between the refrigerant (which is supposed to have the higher temperature) and the ambient air. On a day as hot as that, the process becomes more difficult, but there should still be some function to the AC system.
As for why it worked after you plugged it in, bad connection would seem likely. However, if the compressor cycled for 15 minutes without shutting off, then it's possible you've either got a bad high pressure switch, or there wasn't enough refrigerant to build up enough pressure for it to cut off at the predetermined high pressure and begin cycling. I would probably go with the latter, personally.. 15 minutes of building up pressure in an AC system, and something will happen to where you'll no it. The refrigerant type could have an impact, as well. Your Blazer has an R134a system, which operates at different system pressures than an R12 system. If I remember correctly, when dyed refrigerant is added, it's HCFC22, which is also going to have different performance than R134a would.... although don't quote me on the refrigerant type, because I've never had to use dyed refrigerant in an AC system.
As for the leak, when he went over it with the sniffer, did he probe through the dash vent by the passenger door in order to test if the leak was coming from the condenser? And did he try another halogen sniffer when he couldn't find anything from the first one?
Did he give you the results of the system performance test? If so, what were the high side and low side pressure readings, what was the ambient air temperature, and what was the humidity (if you know it offhand)? I'm assuming he performed such a test with a manifold gauge set both before evacuating and charging the system and after recharging it?
From what I've seen in your post, not really sure I have a warm and fuzzy about the guy you've got servicing your AC system.

No I never asked, Thursday ill ask. He's got a Big Mac tools machine that does it. He's been the mechanic family has gone to forever. So he's legit. Thursday will tell tale and ill ask him to probe that vent. It's not working now so I'm not even sure, compressor won't kick on, which last time he re charged it did for a few weeks till it leaked out. This time it should
Do the same, but nope some reason it's not. Thursday he's Gina have to fix alot more than just the leak it seems if its acting up like this now

After Thursday ill be able to list everything I know. So till tomorrow I'm confused as **** lol. See if he can fix it once and for all tomorrow if not I'm gunna need your help lol