heater switch mystery

[Rocketdog]

Heater switch, er HVAC was wonky when I bought my 87 gl. It required constant pressure to work the heater. I used duck tape for a while until it completely failed me. Upon pulling the HVAC line out, some of its "bearings" were loose because parts of it were melted. I pulled one from another car that appeared fine and swapped it. I also replaced the resistor and heater blower motor with brand new ones. AND GUESS WHAT?! It still acts weird, needing pressure or to be pressed just right to work when you let go. Granted all fan settings work now instead of only the 4th one with the original melted pos. Please, someone tell me what I am missing here.