Just a reminder. Certain codes will disable the AC compressor function. May be why it quits cooling.
Figure out your main problem and the AC should return to normal.

 

Being in Louisiana I would look into post #2, It sounds like corrosion has crept into the circuit and with the vehicles a little is all it takes.

 

I'm going to separate the fuse box and check the PCM connectors today. And yes, it had been EXTEMELY humid here the past couple of weeks.

 

What’s the battery voltage, not with the engine running and the alternator powering the system, just the battery voltage,

 

The battery checks out fine at 12.6 volts. Load tested at 853 amps. Took apart the fuse box, cleaned and applied dielectric grease. Removed connectors from the PCM. Top one looked good, so I cleaned it. Lower one had oil in it. Cleaned several times and air dried to remove the oil. Got a new oil pressure switch( the old one was filled with oil at the connector). I have to wait until tomorrow to get a 1 1/16 6 point socket from work. The 12 point wouldn't get it nor the special switch sockets. Not to mention, there so damn little room to work by that switch. I'm DONE for the day. Hopefully this does the trick and nothing was damaged in the PCM.

 

Somebody a while ago found oil had migrated up the cable to the ECM connector. You also need to check for pins pushing out the back of the connector.

 

All the pins looked good on the connector and the PCM. Hopefully I can change out the oil pressure switch and get back running tomorrow.

 

Replaced oil pressure switch, reinstalled battery and checked for any codes. Took it for a 20 minute run today and no issues or warning lights so far. I will drive it more Wednesday and Thursday to make sure it is good for a 90 mile commute.

 

Ran the car this morning, No issues , and the outside temp was 80 degrees. Took a quick ride down the road this afternoon( outside temp was 95 degrees) and the demons were back after 5 minutes.
I looked at the PCM connector where I had the oil , and there was some oil residue. Cleaned connector again and took a quick test ride. Same problem after 30 seconds. The only codes I had were U0073
and P2544. I will have to start checking the modules behind the kick panel and in the cargo area next.
I read Catman's post about the U0100 code.The video was helpful in giving me a place to start.

 

Drove the car yesterday with outside temps 95-99 degrees with no issues. Drove it 15 miles today and Traction Off, ESC Off notifications, ABS light, Brake Light and Traction Control light s lit. A couple of speedometer stumbles, but hard shifting again. When I got home, I checked the pins on the OBD2 interface (Pins 4 & 5 grounds okay, pin 6 voltage 2.65,pin 14 voltage 2.36 with key on and engine off) Disconnected the battery and ohm reading between pin 6 and 14 was 61 ohms. Pin 16 was always 12.6 volts. I was thinking maybe the speed sensor , but with the speedo working and the trans still shifting hard, I ruled that out.