The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Vintage air Cold out defrost hot out dash vents.

**69GMC2004** · 04-05-2021, 11:57 PM

I can't speak to the Vintage Air specifically, but OEM use the AC compressor on defrost mode (with heat ON) because the AC system will remove moisture from the air and help with the defrost function.

04-05-2021, 11:57 PM	#3
69GMC2004 Active Member Join Date: Nov 2018 Location: SHERWOOD PARK, AB Posts: 113	Re: Vintage air Cold out defrost hot out dash vents. I can't speak to the Vintage Air specifically, but OEM use the AC compressor on defrost mode (with heat ON) because the AC system will remove moisture from the air and help with the defrost function.