Yukon/Tahoe HVAC in Silverado/Sierra

[97redz71]

So the HVAC switch for my 97 Sierra started blowing air only at the ground. So, I went to the junkyard and picked up an HVAC switch that came off of a Tahoe with the rear defrost option. I hooked it up and everything work great. But, my mechanic mentioned to me that the A/C is constantly running even if the switch is turned off. Everytime the trucks is on, the A/C is on. Could the new Tahoe HVAC switch be doing this?

 

[df2x4]

Did you have the windshield defroster selected on the blend knob? That will make the A/C compressor run at all times.

Edited because I dumbed out for a second.

 

[97redz71]

It is not pressed in, so no.

 

[97redz71]

Even though the knob is not engaged, could it still be causing the compressor to constantly run somehow?

 

[df2x4]

Even though the knob is not engaged, could it still be causing the compressor to constantly run somehow?

The only thing I can think of is the defroster being engaged. Not the button for the rear glass, but the position on the knob for the front glass. Try adjusting the knobs so that only the low vents by your feet are blowing, and the A/C button is not pressed in. If the A/C still engages then something's not right.

 

[97redz71]

Sounds good, I will try it tomorrow!

 

[97redz71]

Could being low on Freon cause this also?

 

[Dr.Zoom]

I'd hook up your old controls and see what happens.

 

[97redz71]

For some reason when I did hook up my old console, every setting I put the air blower on, it only blew air at my feet.

 

[Dr.Zoom]

Did the a.c. run all the time?