Here's a couple of more bits of the puzzle.
In the first two pics you can see the routing of the a/c lines. Stock rear air drops down on the drivers side and goes underneath the vehicle near the third door and then routes up to engine compartment. With the 70/80's a/c, it drops on the passenger side making the routing easier. BTW, just got finished repainting the interior this weekend. Slowly putting things back in.
In the 3rd pic you can see the T fittings used to run the lines to the back. This was a bit of a PITA. Doing it over, I would have redone the lines completely to the front unit, as crimping on the vehicle is a bit of a challenge, takes two people, one to hold the fixture and one to run down the crimp.
In the 4th pic is Hollister Road's relay set up for the 2 speed Ford Fan. Can't say enough good things about the quality and functionality. Worth every penny and there were several.
Lastly is a pic of my first attempt at a semi complex relay system. I ran 12 gauge wire from engine compartment (junction block off of alternator, which is a 105 amp unit) all the way to a 20amp fuse block in back. I only ran 20 gauge wires from rear air switch to relay assembly.
