>>The receiver/dryer has 2 switches on it. unplugging one disabled the AC completely (black connectors). Unplugging the other (white connectors) didn't effect AC (still ran and blew cold). When I jumpered those together the auxiliary fan still didn't run..

As I stated , the sw that is the a/c LOW fan at the reciever is the one with the PIGTAIL wires .
Do not disconnect the wires ..just peel back at the connectors and jumper right there [ key ON, of course]

Is that what you have done???