92 cadillac deville a/c

[Jackfitz5]

So I have a 92 cadillac deville that's still r12. The last charge held for a long time maybe a year or so. I am having a hard time seeing if there is a major leak I can locate. However, when I try to charge the r12 I jump the compressor and the compressor runs. Either it doesnt suck the freon in or it sucks air in from somewhere else and results in the pressure being too high to suck in any more freon. Long story short is that the freon in the cans is not getting sucked in. A couple questions. Is it possible for a compressor to run but not be working? I could have fried it by running it dry for so long. I have a long ride coming up and would love to have ac for the ride home. Anybody have any ideas on how I should proceed?

[Jackfitz5]

It even seems as though that it's sucking in air from somewhere else because the pressure gets high enough to run the compressor without a jumper wire. But the compressor still sounds like it is running dry and then the freon can is still full. There is pressure in the hose from the can to the low pressure line

[Cornbinder89]

1st you can't just add if a system has air in it. A/C systems need all the non-condensables out before recharging. A system that leaks down every year has a leak! that needs to be addressed before anything else. If refrigerant leaks out so does refrigerant oil, if you have been "boosting" it year after year, it is likely the compressor is damaged from lack of oil.
Unless you have ALL the equipment to diagnose best to take to a shop that does. If it needs a compressor or if metal has got into the system, it could cost more than the car is worth to fix.
You shouldn't have to "jumper" anything to charge, the 1st can should go into the evacuated system and provide enough pressure to at least start the compressor.

[Cusser]

If the compressor engages without being jumped, I'd be interested in both high and low pressures at about 1800-2000 rpm. If you don't have service gauges and you expect to investigate this successfully, then also buy a lottery ticket.

[Tom Greenleaf]

Late to chime in, some experience with this exact year of DeVille! Odd deal at the time customer did a whole new compressor only because of clutch failure do recall could replace that thru FR wheel well just FYI.

He twice had the hose set tricky on lots of vehicles on crooked there are two different color washers to seal that to compressor! Heard later not all of them - how special.

Leaked like a open hole on vacuum gave it back to customer don't waste R-12 then either. Tried again OMG really louse it up now I took compressor off, new flat garden hose type washers from dealer managed to get it right and unbend the centering tube standing up has to fit in hose connection. Weak spot then apparently new a problem.

Fixed finally done for years till traded for another did know that.

Question and a thing common to these that do NOT use a LPCO switch! It's a thermistor instead both detects low refrigerant pressures by temp not pressure AND shuts down the compressor intentionally till reset by either a scanner/reader or says in English on a sticker on radiator support you can get it to empower clutch for a grace period to charge it by disconnecting battery also lose all pre-sets inside the thing!

It worked after holding vacuum risked it and charged by listed weight never heard again about it let owner's reset insane info center on dash dual settings for seat positions, oil change intervals and 500 more things to bust or go wrong.

All other things must work, fans and system pressures within ranges set by them not you or it just shuts down nothing you can do.

Duly noted GM did make some really stupid stuff and this was one of them no offense it did turn out an OK vehicle,

(edit question: Where did you get cans of R-12 and how do you know it's real? Many hacked or marked as real good fakes are nothing but maybe propane. By now, buyer beware of small cans of R-12. Sold new in only 14oz can by most some made a 12oz one not many! Taps had a lever to clamp to a cap had to stay tight just long enough then leaked out the rest couldn't save it on ANY I STILL OWN! Same top on cans of horns, for parties or ball games could side tap those marked as chemical name pure R-12 just FYI) (one more: If older not stored well the top tap pulls the crimp up leaks so you don't know what you put in at all or what leaked adds to frustration)

[Nacho]

If the compressor engages, do you get any readings? If it does, but needles don't move or do so marginally, it's time to replace it.

[Willie]

Is there a low refrigerant code set? If the system is low on charge, it will set a low refrigerant code. You need to have the refrigerant all hooked up, then clear the code and the system will suck in the refrigerant. As others have asked - what are the high and low side pressures?

[Cornbinder89]

OP'er hasn't been back since he posted the 1st 2 post, I think this thread is a dead end.