Factory A/C Conversion on a Heater Only Car

Good morning, I’m in the middle of accumulating parts for my '68 Cougar. As of now, my Cougar was a factory heater only car. At some point, someone installed an aftermarket A/C conversion kit with a Sanden compressor. So, I have the factory heater controller. I’m assuming they changed the HVAC box to accommodate the evaporator. My question is this: If I acquire all the parts (engine bay and inside cab) from a factory 1968 A/C car (A/C controller, HVAC box, etc) is this switch feasible? Will my wiring harness be compatible with a factory A/C setup?

The reason I ask, is that a lot of the aftermarket parts are falling apart and I don’t know what brand to replace them with, so naturally going to factory would be easier in getting replacement parts for the system.

Or would a better option be to just buy a whole entirely new aftermarket kit and go with that?

Thank you in advance for the input.

– Jeramy

I can only tell you what Mustangs did for AC in 1968: there was a separate AC harness from the main underdash. I’ve refurbished many 67/68 Cougar underdash harnesses and never saw any wiring associated with AC in them, so I suspect the AC harness is also separate from the underdash harness for Cougars.