I believe this is the correct Back-up Wiring harness for a '72 Challenger with 4-speed manual.
The First question I have is the green wire which comes out of the connector at position #4 (in below diagram) should go to the Blower motor?
Also the Blue wire which comes out of position #3 (in below diagram) on the connector, does it go to the drier? It is pretty long.
Here is the main diagram with a red arrow pointing at the connector I am talking about.