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Bob_H · 06-28-2015, 05:01 PM

Bringing this back to life with a new but related question.
I have hooked everything up in my 71 factory air GMC. The two port valve opens when the lever is in the full drivers side position - which states "inside" air flow, yet that is when it opens the various flaps to let fresh "outside" air in. Bottom line -it is working opposite of the intended way - as is the entire top lever.
Ideas?
It will come out the "defrost" vents when it is on the drivers side, and the "AC/heater" vents when put to the pass side. This is opposite of the labels on the AC panel.
It seems the two way vacuum valve should be open in all positions except "inside" air - but that is not how its working?
I'm all ears - trying to get it all working properly.

06-28-2015, 05:01 PM	#10
Bob_H Registered User Join Date: Jul 2014 Location: Greensboro NC Posts: 22	Re: A/C Heat Vacuum Hose Routing Bringing this back to life with a new but related question. I have hooked everything up in my 71 factory air GMC. The two port valve opens when the lever is in the full drivers side position - which states "inside" air flow, yet that is when it opens the various flaps to let fresh "outside" air in. Bottom line -it is working opposite of the intended way - as is the entire top lever. Ideas? It will come out the "defrost" vents when it is on the drivers side, and the "AC/heater" vents when put to the pass side. This is opposite of the labels on the AC panel. It seems the two way vacuum valve should be open in all positions except "inside" air - but that is not how its working? I'm all ears - trying to get it all working properly.