67 Barracuda Heavy Electric Load
I like puzzles and have a few minutes to look at this again.
Here's what the wires in the photos seem to be.
The black wire with the other in-line fuse - I don't know where that goes.
But it only makes sense that the relay is feeding the red wire going past the battery and onto the fan.
The relay we see on the firewall only has 4 wires. So that's just one relay. If there is one for the headlights, its somewhere else.
I'm going to guess the other red wire is M&H replacement harness continuation of the battery circuit A1B. It should go the fusible link and connect through at position Z on the firewall.