My heater wasn't working on my 72 , so i removed the dash pad , checked for power going into the heater switch, which there was but no power coming out . I removed the screws holding the heater control pad to the dash , then removed the switch from the heater control panel. Turns out the switch opens when you stretch open the couple small clips and the parts are very basic. All the contacts were exremely coroded , using a 80 grit sanding attachment on my dremel tool I cleaned all the contacts and reassembeled everything . All heater controls work now . You can probably buy the switch but you can take it apart and clean it in less then 5 minutes .