73 Heater wiring- please help.

[73rallye440magnum]

On top of my heater box there is a single green wire with a male connection on the end. Is this the power supply for the blower motor? Where is its female companion? I did not disassemble this car and this heater has got me stumped. Any help would be appreciated. Pictures? Thanks! Jake

[Nacho-RT74]

blower source... yes... runs to the bulkhead conector and use one of its cavities. Normally on 72/73s is used one of the tranny harness section, what still leaves one cavity empty