No not at all. I was confirming what you said. All Good,

Wait, were we arguing? :-huh

I. had misread your post and interpreted it incorrectly. After I reread it I confirmed I didn't read it correctly. All good 😊

I believe this is correct about the mix of the two along with moisture entering.. Of course not evacuating the system after opening, moisture entering can cause black death. I think the difference in compressor oil may also contribute to this but I am no HVAC expert. If the A/c system is going to be opened for conversion, the orifice tube can be checked for black death and if present the system should be flushed thoroughly before converting to R134a.

So yea i see no stickers and the low side has a 134a but the high has r12 service port. I messed with the clutch cycle switch and I tightened the thing by hand will that have any affect on the AC system? I can’t start the truck right now so I can’t test it.

https://cimg1.ibsrv.net/gimg/www.for...79acf6fa54.jpg

What you did with the clutch switch will not effect the system. Since you do plan on converting the system, I would remove the orifice tube to see if it is gummed up. It might change your procedure for converting if you have to flush it. After I saw the black death and what it entailed to remove it, I replaced everything with new parts. A/C is almost imperative where I am.

Ok. Is the tube the one on the bottom of the ac dryer?
and is it possible that there’s enough charge it will explode refrigerant or Freon everywhere?

Mine is inside this tube. You will need a quick disconnect to get it off as I recall.

https://cimg1.ibsrv.net/gimg/www.for...b005e7be82.jpg

Do not uncouple the hose. Since you still have not connected gauges…you do not know if anything is in the system.

You know that the electrical part is good since jumping the low pressure switch engaged the compressor clutch. At this point you probably should be taking the truck somewhere to have the system evacuated. I would think the system was filled with R-134a but there is no way to know. Let a professional figure out what is there and recover it. You can replace components and then take it back to be filled.

Just test pressure by pushing on the valve stem in the low side, if you have pressure, you will know.

How much pressure? Sort of empty or enough to spray refrigerant and oil all over him?

Ohhh, I don't know, probably enough to actually blow the hood off the thing.

Maybe cover the value with a rag to keep it from spewing. It's a short press, not trying to drain it if it is full.

I assumed the A/C system was done and empty since an R12 fitting was still on there along with a R134a fitting. If it still has refrigerant in there it should be evacuated before opening.

I tend to agree from what I am reading, it sounds and looks like it is empty.

Again, a quick check on the valve will tell the story.

I'm inclined to agree. A quick press of the valve seems reasonable. If it hisses and has refrigerant, it should be evacuated before removing the orifice.