Tonight I spent some time trying to unfreeze the CDL lever and get it to slide to and fro, and hopefully achieve/restore the locking diff functionality ahead of the coming winter. While it slowly starting to gain some movement a 1/16 of an inch a t time it occurred to me that since this is an automatic HVAC system there may be no way to get the AC to operate when the ambient temp is below 60°F? I pressed AUTO and dropped the temp to Lo and the air was presumably 46° coming out of the vents, simply because it was 46° outside. I went around to the front of the truck and the condenser fan was not spinning and neither was the compressor clutch. I like to run the AC in the winter from time to time to not only dry out the cabin when necessary but for the health of the system, to keep the refrigerant cycling and lubricating the seals. Either my AC charge is low (bummer), or my theory is correct. Is there a way to force the AC to come on? The Owner's Manual didn't seem to say there was a way.

 

Try putting the vents to defrost, that should cycle the A/C system as you need drier air

Running A/C in the winter on a system not designed for it, can slug a compressor pretty fast. There might be too much cooling ability in these condensers to for the system to run. I wouldn't worry about the seals and such, they've been designed to seal with or without refrigerant.

 

 

If you put a hair dryer/heat gun on the ambient temp sensor the fan comes on to assist the A/c at over 80 degrees or something like that, or it comes on when coolant temp is 210.

Moght be simpler just to test it with with leads and your battery.

 

Or just jump the relay

 

CR, when you say ambient temp sensor, that's the probe near the drier? I thought the condenser fan came on anytime the AC was active (or engine temps dictated it). Good to know.

Great idea for the relay. Thanks.