Air Conditioner not working?

Rear A/C vents blowing cold air while front vents blow warm air. What could be causing that?

My Uplander's AC doesn't work, I can start the vehicle, the ac clutch comes on, the cooling fans turn on, the ac clutch turns off. No cold air comes out of the vents at all, I checked the pressures and have about 105 psi on the low side and about 365 on the high side.

That could be the case, because I let my son borrow it for awhile, twice. He might've done that this second time, I'll see.

The first time he had it in the winter, he brought it back in the winter months, and I noticed the cooling fans would come on about 10 seconds after starting it. They would, and still do, the entire time you're driving the vehicle and don't shut off until you turn the key off. So it is exhibiting the same behavior, I'm just not sure of the ac clutch starting or ac pressures because you don't use ac in the winter. Could there be a switch problem somewhere that is the primary reason this all started? It also has rear ac, if that matters.

I'll call the Chevy dealer here tomorrow to have it checked out.

I'll make sure I post back on what they found.

I spoke to my son this morning he said he did add some, the last time he borrowed it, which was in the summer. He said he noticed the fans coming on like that in the winter but thought it was normal. With that being said, is there an underlying cause, that would make the fans come on and stay on like that even in the winter? The engine doesn't run hot, it hasn't been overheated, the coolant level is normal in the recovery tank.

Let's just say I go out, start the vehicle, leave the ac off, and all the rest of the blower, defrost, etc. Off. What would cause the fans to act like that.

Thank you for replying so quick too, I appreciate it.

For the last year or so the AC has been having problems, It works fine on cool cloudy days or at night, but during the day when it is in the eighties it works off and on, the air will go from upper fifties to eighties or nineties. I checked the low pressure side, when the compressor is running on an eighty degree day, the low pressure is 35-38 psi. The compressor will run sometime sixty seconds then shuts off for about ten seconds. On hot days the compressor will only run for a few seconds at a time. Cool nights the compressor will run continuously and the temperature from the vents will drop into the fifties. I cant figure it out, during the hot daytime it will not cool, after a few minutes driving it will cool slightly but the vent temperatures are about eighty degrees. On old
Fords they had a Freon switch that would switch the compressor on and off if the Freon is low but according to the readings it should have plenty.

Autozone, just scanned it about 10 minutes ago. There were no codes, it has no check engine lights, and I can assure you no one has done any wiring to the vehicle, except GM when it was new.

I understand the circuit, but I don't see the logic that tells the ECM to turn the fans on, other than the IPC telling it that the engine is hot.

Is there a sensor that is telling the IPC that the engine is hot located on the engine somewhere?

Looking closer at the engine, the fans actually turn on in slow first after approx. 6 seconds, than the fans go into high speed approx. 4 seconds later. I swapped the relays around making sure the ones I swapped were the same as the ones I was swapping to. They all showed the same symptoms, so I'm pretty sure its not a relay problem for the fans. I unplugged the ac relay and the clutch doesn't engage at all, like it was previously, but it still followed the process it was before.

Do you know the location of the ac pressure switch on this vehicle so I could do a visual of it.

Air Conditioning problem 6 cyl Front Wheel Drive Automatic 96000 miles

Hello, the A/C in my '07 Chevy Uplander (96,000 miles) has quit working. The A/C light inside turns on and under the hood the Compressor kicks on and seems to be running properly. The low side line is cold and the pressure (checked with one of those cheap gauges on top of a recharge can)(picture below

) shows at the top of the blue "filled" area. However, when I pulled the gauge off the port the refridgerant was green. Is this normal? I have had the vehicle since it had 36,000 miles on it and hasn't been serviced as far is I know.

Is the PCM looking for a normally open or normally closed from this switch?

So I could unplug it and see if the fans act normal?