Why does my heater not work?

Thanks for the suggestion. What is the temperature control and where is it? Part of the heater? CDACAM

Need to determine what type of system you have , cable or electronic controls (I don't have that info handy) , sorry. Next would be visually inspecting under dash , checking what items are visible (might have to remove lower covers) and which are responding to which controler(temp door , fresh/recirculate , mode -defrost-dashvent , floor etc. The whole SYSTEM is what you are inspecting , not just a single part.

Great. Thanks. Sounds like a week end spent on the floor of this great old car.

Have patience , a bright flashlight and the right pair of glasses(if needed). A helper to work controls while you observe would make things easier.