elopez2

Guys I have a Silverado 4.8 eng-4X2. Everything is good on it but I have notice that when I turn on the heater (sounds like AC-Compressor is coming on) Has any one seen this issues on theres trucks? Is this normal?

wrparks

I wouldn't be surprised at all. If it has the cabin air recirculate button, try toggling that. I'm pretty sure that if it is set to recirculate it will run the Ac compressor to adjust the air humidity and comfort level, but it may be the opposite. Also, when set to defrost it should automatically come on.

elopez2

It really doesn't matter if it's on recirculate or if it gets the air from outside. Is every single GM truck like this?

wrparks

I don't think it should always be on if running the heat. You could have a bad switch on your recirculate toggle button?? Are you sure it's coming on? You said "sounds like", have you looked to see if the compressor is running under the hood when the heat is on?

2000CAYukon

Compressor will be on if any air is going to the defrost vents.

//2000CAYukon

vnotaro

Correct.

elopez2

No sure why GM made these trucks like this. On my truck is not only the defrost vent, that compressor turns on. Compressor kicks in all the time no matter what setting you have it on. I will visually check if compressor is engages.