You really need an 81 FSM for this stuff. Personally I'm much more familair with the 83+ wireing because it's a lot more common. I don't know what that timer or that relay are for.
I would guess that this mini-harness and fuse tube are for some accessory that was after-the-fact but dealer installed. Like AC or Cruise control. It appears that it's only point is to intercept a main power lead, run it through a fuse, and to....?
If it were me I would probably remove this mini-harness and just connect the two ends together. Make note of where it came from in case you need to put it back in later :-p.
The combo switch does not need to be grounded. You are going to have to trace the circuit. You need power at the lights. The switch turns on and off the *ground* for the lights. Subaru used a ground controlled lighting system. When the ignition is on the bulbs should always have 12v present. They should only be grounded when the switch is on. Check for +12v at the bulbs. Then try grounding the other side - it should come on. That will narrrow it down to the power supply or the ground switching.
There should be at least one or two grounds (ring terminal style) under the dash that are for the lights. And of course the relays.
Edited by GeneralDisorder, 24 December 2011 - 12:34 AM.