Heater/AC Control Problem

[CO/6]

My '71 Valiant's Heater/AC control isn't working when I hit the defroster button. Everything else works great. Feels like the button is "sticking". Is there a fix, or am I in the market for a new one? I could give a darn about AC or heat, but I need to defrost the windshield in the morning. My ears are freezing from driving with my head out the window.

 

[speedyb-cc]

If it's like my 72 Dart there is a rod coming down right side, next to the floor outlet, pull it down,or push up? and leave it there for defrost. You may have to leave the push button on defrost so the other vacuum doesn't pull it off defrost.
Hope this helps.
Bruce