When does the ac compressor run?

[Jstcruz]

Im having a brain fluffy at the moment lol. Can anyone inform me of what setting on the climate control selection does not run the compressor? I know most of the settings run the compressor to dry the air, but If i want heat i think its a waste to run it unless I need defrost. Thanks guys!

 

[deadernie]

I thought it only ran during AC and defrost.

 

[sportblack99]

I'm not entirely sure on our trucks bit the semis at work run whenever the hear, defrost, or a/c is on. Doesn't cycle near as much on heat or defrost of course but just dries the air. I believe our trucks are just a/ and defrost.

 

[colintrax]

Check the owner's manual. If I remember right the top fan is the only one that won't turn on the compressor. Floor, floor/top vent, defrost, ac all turn on the compressor

 

[deweyville65]

Here we go again, just like last winter. Yeah, the A/C is supposed to dry the air when in defrost. Also runs to keep the seals lubricated. I just unplug the compressor in the winter, cause when I want heat, I want heat. I dont want to warm the cold air from the A/C to defrost the windshield. Yes, the factory designed it this way, but in the days before big brother knew more than we did, the A/C was seperate. By the way, when I first started driving semis, we didn't even have defrosters. We had a fan on thedash we couldblow towards the windshield for defrost. Was crude, but it worked, sort of.

 

[2000StreetRod]

panel & floor

The A/C compressor does not run for the panel and floor positions. For other positions (except A/C and Max A/C) the compressor only runs when the outside air temperature is 50 degrees F or greater.

 

[Jstcruz]

Alright cool, good info. Kind of makes me want to put a switch on it. Thanks for the comments guys!

 

[budwich]

The A/C compressor does not run for the panel and floor positions. For other positions (except A/C and Max A/C) the compressor only runs when the outside air temperature is 50 degrees F or greater.

Hey streetrod.... good answer.... small question, I assume the 50 degrees F is because of "charge chemistry" (ie. if your system is FULLY and correctly charged) then certain "physics" occur that prevent or allow that temperature... cause I don't see a temperature element in the circuit.... is this correct???