1993 940T compressor locking up

Well, the saga continues with this lemon 940T. I'm not going to go into it all but I NEVER had this much trouble out of my 240's after 35 years of driving them. I had a 1980 240 that I had for 23 years! oil changes, brakes, clutch is all I ever did to it.

The latest problem is that the AC compressor is locking up. Random, at speed or, slow driving. Doesn't seem to follow any pattern. Anyway, After getting a pinhole in the condenser, and having an AC hose break, I finally thought the AC was good. I was hoping it was just a loose belt screeching. It's not a loose belt. Unfortunately, I haven't gotten a chance to actually raise the hood when it is screeching . It always happens while driving. Any help is appreciated.

Gotta put gauges on it but your description of 'locking up' says compressor failure more than Freon.

Do the gauge thing anyway and report back.

May be the High side pressure goes crazy due to overcharging or insufficient condenser cooling (is the fan ON?) or the orifice tube/ expansion valve bad.

Thanks for the responses. Haven't put gauges on it yet but, AC is my weak link on my car repairs. I've never taken a car to a shop for anything except for AC and tires. I just drove it and, of course it didn't screech so I could pop the hood and have a look. Anyway, my brother has gauges and a little better understanding of automotive AC so, I will report back after I check the pressures.

Also, the fan does run.

I'd bet it has internal damage and is locking up mechanically. It could also be drastically over-charged and hydrolocking, which may well mean internal damage at this point too.

Refrigeration is actually fairly simple, I avoided it for a long time, dreaded messing with it, then I read up on how it all works and it turns out it really isn't that hard. Bought a manifold at Harbor Freight, bought a vacuum pump for $30 on ebay, I've serviced dozens of AC systems with pretty good success. The key is cleanliness, good seals, replace the filter/dryer if the system has been opened and pull a good vacuum to get all the moisture out prior to charging. I usually let the vacuum pump run for an hour or two and then close off the valves and make sure it holds for at least an hour with no perceptible drop, then charge it.