How much refrigerant is needed to kick the ac clutch on for an empty system?

[565bbchevy]

TEST- Pull the plug to the relay. Find a green and green/black wiring. Put a temporary jumper wire across the plug into the wire socket. Since this is the only real wiring you'll be needing without the ECM, this should tell you if the clutch will engage when you turn the system to Norm or Max or whatever with the key on and enough pressure in the system to keep the cycling switch closed. If it doesn't, you got another issue to deal with.

Post #39 did that already and the clutch clicked

 

[69hurstolds]

Post #39 did that already and the clutch clicked

Sorry, I must've missed that in all the smoke and mirrors...

So now you make the choice...

It's on you now, cowboy!

 

[565bbchevy]

Well for the heck of it I grounded the brown wire from relay and still no power to the clutch, so I guess it's goodbye to the relay and i will clean up my wiring and finish charging the system this weekend.

 

[Lowdollarbuild]

So my AC system has all new everything on my 86' Regal, it holds just under 30 lbs of vacuum and after pulling vacuum for 45 minutes I went to add refrigerant to the low side and it took it very slow maybe 15 minutes and didn't even take a full 12 oz can and this is about where the gauges were when I shut it off with the clutch never kicking on.

View attachment 116361

Might help if we knew what you're working on & any mods made