Anyone find a way to engage A/C compressor when below 40 outside?

[J Mac]

If there is one thing that bugs me about my Yukon it's this! Last night had 7 of us in the Yukon while it was snowing. Defrost was on high but all the windows were fogging up. Outside temp showed 35 so of course the compressor won't kick in to help dry the air inside. Had to crack the windows which had the kids complaining...especially at 60mph. I know the reason is to protect the compressor or something like that but it's a PITA!

 

[Joseph Garcia]

Below a certain temperature, to A/C compressor with its refrigerant is not effective, so it won't run.

 

[Doubeleive]

that's when you have to go old school and use a rag to wipe the window, but yes the ac should act as a dehumidifier, maybe unplugging the ambient temp sensor would work but it's not really a viable solution since it is behind the grill.

 

[OR VietVet]

It has been below 30 degrees here for several mornings and when I start the rig and use the defrost it does clear my front window and the compressor is not on. We have a drier climate and the humidity there in VA may still hinder the process, even at 35 degrees. I think......

 

[Bill 1960]

How is blowing up your compressor because you slugged it with liquid refrigerant going to improve your situation?

Secondly, when cool air is heated the relative humidity decreases naturally. That’s why dry indoor air is such a problem in winter.

I suggest checking to be sure your blend doors and particularly the door that switches between recirculating and fresh air is working as it should. Sounds like not enough fresh air intake, especially since opening a window relieves the condition.

 

[SnowDrifter]

Yeah you don't want to do that chief.

That limit is there because of the saturation temp/pressure. Lower than that and the thing is going to lose phase separation between gas and liquid state. Ever seen what happens when you hydrolock an engine? Same gig in your compressor.

Meanwhile I'm wishing I could find a way of turning OFF the compressor when I have defrost on because I like to run defrost out the vents but don't want the compressor running lmao

 

[OR VietVet]

Yeah you don't want to do that chief.

That limit is there because of the saturation temp/pressure. Lower than that and the thing is going to lose phase separation between gas and liquid state. Ever seen what happens when you hydrolock an engine? Same gig in your compressor.

Meanwhile I'm wishing I could find a way of turning OFF the compressor when I have defrost on because I like to run defrost out the vents but don't want the compressor running lmao

Can't you just unplug the low pressure switch? Or run a toggle switch inside that is inline with the low pressure switch wiring. McGyver it!

 

[J Mac]

Yeah I don't know enough about the A/C system and definitely don't want to screw it up. This is the 2nd 04 Yukon I've had and they both perform the same. All other vehicles I've had and the 3 others we have now, none GM's, all have the ability to run the a/c with the defrost. In fact, the A/C comes on whenever the defrost is turned on. Even when cold out. So why is the GM system so different? I'm sure a lot has to do with the high humidity we have here. I was just wondering if there was a MaGyver trick that worked and didn't screw up the system. Guess I'll stick with the rags!

 

[SnowDrifter]

Can't you just unplug the low pressure switch? Or run a toggle switch inside that is inline with the low pressure switch wiring. McGyver it!

I could.... But that's cheesy

I actually looked into programming the BCM but couldn't find any information either way

 

[89Suburban]

Yeah I don't know enough about the A/C system and definitely don't want to screw it up. This is the 2nd 04 Yukon I've had and they both perform the same. All other vehicles I've had and the 3 others we have now, none GM's, all have the ability to run the a/c with the defrost. In fact, the A/C comes on whenever the defrost is turned on. Even when cold out. So why is the GM system so different? I'm sure a lot has to do with the high humidity we have here. I was just wondering if there was a MaGyver trick that worked and didn't screw up the system. Guess I'll stick with the rags!

Maybe one of these will ease the pain, make it a lot easier. I keep one in the storage pocket behind the driver's seat.

https://www.amazon.com/Invisible-Glass-95161-1-Piece-Reach/dp/B0017K69MA/ref=asc_df_B0017K69MA/?tag=hyprod-20&linkCode=df0&hvadid=309722106657&hvpos=&hvnetw=g&hvrand=462722148018951837&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9007372&hvtargid=pla-435416696635&psc=1&tag=&ref=&adgrpid=60862488719&hvpone=&hvptwo=&hvadid=309722106657&hvpos=&hvnetw=g&hvrand=462722148018951837&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9007372&hvtargid=pla-435416696635