Vintage Cars: a/c heater buttons, key cylinder, actual control

Question
yo ron its me again. i got another question for you. this time it is about the a/c and heater switches. i press the defrost button and it blows but when press any of the buttons below they dont work could it be a fuse? by the way the seafoam worked great and the instrument cluster came out fine i got it repaired and i know know how many mpg i get.

Answer
probably not, either the actual control unit or the temp sender from the engine ( interlock temp sender ) or the ignition key cylinder.
Default is defrost , so that will alwyas work is the circuits fail
the three that make it work
1) key and ingniton  try wiggling the key  when car it up to temp to see if it "comes to life"
2) interlock sender bad ( on top of  Tstat )
3) ACC unit  - bad