Originally Posted by nstg8r
You have to design a new circuit with power coming directly from the battery and triggering it with a relay using the high beam power. If you just try to tap the power from one circuit to the other without isolating the circuit with the relay, you will have your high beams on when you turn on your fog lights.
Yea I've been studying the diagrams this evening nstg8r. Looks like the Legacy/Outback circuit is a reverse of the Impreza circuit. Power on the Impreza has to go through the DRL relay and resistor before going out to the high beams. Legacy and Outback has power on the bulb side of the circuit so it passes through the relay and stepdown resistor last.
It makes sense now how they are able to do this on the Impreza because if you disconnect the DRL resistor your high beam line is effectively cut until the relay switches over and your left with a 12V line to run your fogs.
If you do the same thing on the Legacy, because of the position of the relay in the circuit, you create a direct shot for the highs through your fogs.
I think that is right but feel free to correct me if I'm wrong.
Seems a bit strange that Subaru would wire these circuits differently between product lines but that's the way it reads in the diagrams.