On my 1981, the blend door actuator is behind the glove box. Pull the glove box insert out, and you should find a threaded rod attached to a clip. I had to do this a while back... I think you can un-clip the threaded rod to move the blend door. Find some way to make it stay where you want it.
You might want to note where the rod was attached to the clip, so when you want to put it back together it will be adjusted correctly.
Going to try that this weekend . Thanks . I do have a line disconnected that coms from the brake booster area in the fire wall that I found disconnected. It’s a little bigger than the other vacuum hoses and has a yellow stripe. I thought it went to the cruise control servo as the cc doesn’t work either. It’s a mess
Ok so parking break releases when I step on the main brake pedal to shift out of park. What is this mystery hose supposed to be connected to?comes out of fire wall under brake booster. Not attached to anything in the engine bay