[SS Tim]

Originally Posted by daves72C10D

Not to hijack the thread, mine is sheared off at the firewall. I have not looked at a manual, how hard is it to fix?

You have to pull the cowl panel to access it. See page 1A-35 of the 72 service manual linked above.

Originally Posted by Andy4639

I did away with mine and sealed it up. The AC works fine as does the heat.

Andy, It is not a redundant part or function. If you sealed the valve opening up all you are doing is recirculating cab air all the time.