OK, learning more. On the 84 panel, the relay next to the Rear Defrost relay is the Heater Fan Blower relay, below.
Bad news is that this puppy costs $300 and my control panel harness is not equipped for it anyway. I do want to use the heater blower, so I need to figure something out.
I know the blower was intended to be activated by a switch attached to the heater lever between the seats. I don't have this now, but was planning to install some sort of switch. I guess my question is, do I really need the relay, or can I just wire a switch that activates the motor directly without a relay?
Roger