So it's a dual zone system?
Does the A/C clutch actually engage and the compressor is turning?
Maybe have someone inside press the switch while you watch the compressor.
If the compressor is turning, the small tube should feel hot, the larger one cool.
Check them at the firewall too.
3rd row A/C? Is it blowing cold?
If the small tube isn't hot, compressor may be bad, but not the most likely culprit.
Most likely no charge.
I've had to replace the Schrader valves due to leaks, and also the evap.
If there is no or low charge, put leak detector dye in.
If the evap is the leak, you may see the dye around the condensate drain opening.
If it is the evap, it won't be cheap. Parts aren't much, but the labor is.
Actuators are visible. Drivers side, remove the bolster under the steering wheel.
Passenger side, remove the glove box.
If you're going to recharge yourself, be aware that if refrigerant leaked out, air can leak in.
There is no sight glass like older systems, which is why the charge is weighed
Once you're sure there are no leaks, best to have the system evacuated and the proper charge loaded.
BTW, after the evap replacement, new dryer/filter and recharge, frostbite is a real possibility in mine. I think it's colder now than it was when new.

 

In regards to question 1, I don't see anything in the manual about a low side pressure sensor, so I'd guess "Pressure 1" would refer to the high side. You may already have this info, but I'll post in here for others:

OPERATION
The A/C pressure transducer monitors the pressures in the high side of the refrigerant system through its connection
to a fitting on the A/C discharge line. The A/C pressure transducer will change its internal resistance in response to
the pressures it monitors. A Schrader-type valve in the discharge line fitting permits the A/C pressure transducer to
be removed or installed without disturbing the refrigerant in the A/C system.

The powertrain control module (PCM) provides a five volt reference signal and a sensor ground to the A/C pressure
transducer, then monitors the output voltage of the A/C pressure transducer on a sensor return circuit to determine
refrigerant pressure. The PCM is programmed to respond to the A/C pressure transducer and other sensor inputs by
controlling the operation of the A/C compressor clutch and the radiator cooling fan to help optimize A/C system
performance and to protect the system components from damage. The PCM will disengage the A/C compressor
clutch when high side pressure rises above 3082 kPa (447 psi) and re-engage the clutch when high side pressure
drops below 2937 kPa (426 psi). The A/C pressure transducer will also disengage the A/C compressor clutch if the
high side pressure drops below 110 kPa (16 psi) and will re-engage the clutch when the high side pressure rises
above 221 kPa (32 psi). If the refrigerant pressure rises above 1655 kPa (240 psi), the PCM will actuate the cooling
fan. The A/C pressure transducer input to the PCM will also prevent the A/C compressor clutch from engaging when
ambient temperatures are below about 4.5° C (40° F) due to the pressure/temperature relationship of the refrigerant.

The A/C pressure transducer is diagnosed using a scan tool. Refer to 9 - Engine Electrical Diagnostics for more
information.

 

Great advice, thanks to both of you. Definitely gives me something to go on. And yes, no way will I do the recharge myself.

 

I'd grab one of those bottle from walmart with the gauge on it and plug it into the low side, just to see whats going on with a cheap gauge. low side is along firewall on passenger side,.. if its low, squirt a little in to see if the clutch clicks. i needed three bottles in mine, with the rear AC it holds quite a bit. I think i could add more but do not want to push it... with the quick connects its not as scary as it used to be

 

A good idea. Seems like a cheap way to diagnose it. But then, it would make sense to have a pro evacuate and refill, right? I wonder about air or moisture in the system--or if there's enough oil. Right now, I'm guessing a leak, probably in the Schrader valve--that would allow me to test it, at least.

 

If you suspect a leak, check out the area from this post as well. Commanders (including mine) are notorious for leaking there due to exposure of the AC lines to the elements: Help loosing strange liquid.

 

Very helpful, that's another place I'll look. IF it's leaking there, is there any other way it seal it up? I'm wondering if cleaning it up and putting new clamps might help--or if there's anything that could be injected into between the hose and the filling.