Im not sure how they work in my 64. I have an owners manual for a 66, they look the same. Anyway I read the manual and Im still not sure.


How do I get heat?


How do I get defrost?

 

Read it again? It is tough to remember which is which, but iirc the leftmost Heat control simply brings outside air in versus recirculating. The right Temp control opens and closes the heater hose valve into the core. The On/off control will direct air to the windshield when pulled out.