Heater Wiring - Please Help!

[truckster]

I'm rewiring my Blazer (72 CST w/AC) and there are some things I can't find on the wiring diagram I'm using. This Blazer has been apart for seven years, so I don't quite remember all the details of how it was put together. Aside from that, the PO had hacked the wiring harnesses to bits, which is why I'm rewiring it in the first place.

In the first pic, I believe the brown wire goes to ignition fused.

In the second pic, there's a relay on the right side of my heater box (the relay isn't shown on my wiring diagram) and it has a heavy orange wire. I believe this one is also ignition fused.

In the third pic, there is a connector with green and yellow wires behind the heater box. It's not really long enough to go anywhere, and I can't figure out where it's supposed to connect.

Your help is greatly appreciated.