'66 w/no air conditiong:

Heater doesn't work. The switch on top of the air conditioning? control panel activates a fan, which blows strong through the vents. Is that motor the heater motor?

 

Yes.

 

in my model (guess yours is the same) there is a switch at the top that goes left/right. Middle position is off. left and right are 2 different speeds of the blower motor.
then you have directly below that a panel with 3 sliders (vertical). one is for temperature, the other for floor/windscreen (where to blow) and the third is the fresh air vent (get cold air in or no)
if the heat is not working at all:
check first of all if the hoses going from engine (2 of them) go to the firewall. behind the firewall there is the radiator. If they're there, then this thing should get warm. (feel the hoses when engine warm)

when the blower works as well then it actually should work. check from the back of the panel with the sliders where the wires are hooked up to, you'll figure then what they're supposed to do. In my car I was missing:
both hoses going to radiator inside (it was bridged), the heater plenum, the 2 plastic hoses going from heater plenum to windscreen. i suppose it was never cold in california ....