Fresh air intake for HVAC 85 K5 Blazer

[m85blazer]

Greetings All

Looking for information on the fresh air intake for the HVAC on my ole Blazer.. I am aware of the one on the passenger side kick panel, but is there another one under the cowl that's not easily seen? My box has been butchered by the PO and some of the pods are missing as well as the blend door for Max air is missing.. All i am really needing is the defrost to work correctly and be able to switch it to the dash vents when i want to run the AC that i still need to get working correctly. I am OK with it just pulling from the cab and not outside air. Just want to be sure i don't have another door opening allowing outside air in.

thanks in advance for your help.
rick

 

[6872xtc]

Yes there is a vacuum operated door in the cowl. I believe that I is spring loaded to go open, allowing fresh air in, unless vacuum is applied to close it at the same time as opening the one in the kick panel.

 

[m85blazer]

Yes there is a vacuum operated door in the cowl. I believe that I is spring loaded to go open, allowing fresh air in, unless vacuum is applied to close it at the same time as opening the one in the kick panel.

Thanks for the response.
How can i get to it to keep it closed?? from the inside or do i have to remove the cowl cover in front of the windshield.
I have looked but I guess I'm not seeing it. :/

 

[6872xtc]

I am pretty sure that you have no other option but to pull the cowl panel, and come up with an idea to make it stay in the closed position.

Keep in mind that my old butt could be wrong, memory.....


I personally would try to make it work as factory, which would give you options. But I understand how that can be frustrating, too.

 

[paratrooper307]

Pulling the cowl cover off is the way to get at it. If you decide to rebuild it, the parts are available. It's fairly simple, with the two doors, the manifold/switch for the dash, the vacuum storage tank, and a vacuum source.

 

[m85blazer]

I maybe forced to go that direction. the PO must have replaced the heater core as the top mount on the box under the dash is cracked and pulled away from the firewall slightly. i noticed that last night when i was trying to find the fresh air door. I also noticed when i pulled the part of the box that goes from the airbox to the dash vents that the blend door thats behind the main door (i guess it is anyways) is missing. At this point all i am trying to do is at least get the defrost and dash vents to work correctly.