1999 9200 Air Conditioning has me stumped

Make sure the lines are all hooked correctly. If you didn’t flush the lines, maybe debris is stuck in expansion valve. No need to fill upside down. First 1 or 2 cans shouldn’t hurt it. Adding upside down can split compressor open. Not worth risking it. Be patient and let it pull the refrigerant in, can right side up. The new cans have a safety valve on them so they can’t leak out, after piercing. Make sure you’re using the adapter correctly. Might need a new style adapter. The compressor won’t cycle off till pressure is high enough. High pressure switches vary some are really high, before kicking in and cycling the compressor off. Fan switch should also kick fan on about the same time. New compressor probably has oil already in it. May need a bit more oil. Only way to know is to drain old and new compressors. 1 oz will stay in old compressor. Add 1 oz for each line. Rough estimates at best. Too much will displace refrigerant and cause compressor to run hot, it relies on refrigerant. Less oil is better than too much. I think the rule is .07% oil max. vs. refrigerant. I added 3 oz oil w/dye in mine, when I did the exact Job your doing. I had flushed the lines, replaced everything else. It holds 55 Oz. It’s a grey area, since oil usually stays in parts when replacing just a compress. Often just the high pressure hose coming out of the compressor get contaminated. Check out Video on YouTube ChrisFix AC. Make sure you’re using gauges right.

 

How much freon did you actually put in it?

 

I don’t have a scale, but it popped up to the numbers I posted in about 10 seconds. I’ve done my other trucks and we’d add a little at a time but it took longer than 10 seconds. I had this issue last week before I put the expansion valve and evaporator on. The clutch never cycled just stayed on.

 

Check the bottle/tank which could be very low or empty. A 30lb cylinder typically weighs 20lbs when empty.
What was the reading on the low side when the freezing/frost started?

 

My guess is you are very low on freon.
If you only charged for 10 seconds like you said.
Bottle upright it will take 20 minutes or better to charge with the engine running.
Try it and see if the low side starts dropping and the high side starts rising.

 

Low pressure equals or close to high pressure is what should happen in a properly charged system when it is not running. So it is as IF the compressor is not working even though the clutch is engaged. I would first do what @Star Rider states in post #8. If there is no change in the readings then the compressor is bad either out of the box or damaged from charging liquid on the low side with the compressor running.

 

Have you tried charging it again? Pressure on low side will continue to build up until clutch disengages .70 is high. No telling how much liquid you put it. Evacuate and start from scratch, can upright.