Thanks for the link Katfish. I check that diagram in the link and it to shows slots 3 and 4 in the bulkhead connector as blanks too
This got me thinkin (very dangerous) and I may have just solved my own problem.
I found a blue and dark green wire taped together that is on the far left side of the dash, near the headlight and wiper switch. The green wire connects back to the blower moter resistor and the blue wire must be for the A/C. These match the wiring on the engine side of the firewall that goes to the blower motor and a/c compressor. The connectors look like they will fit into the blanks on the bulkhead. Guess since the heater harness was not part of the main harness, it could not be wired into the bulkhead directly. I'll unwrap the tape that has the wires near the wiper switch and hook it up tomorrow. Pretty sure this solves the mystery! Thanks