What's wrong with my low beam headlights/switch/relay

The daytime running lights (drl) feature seems to function correctly, but when I move the headlight switch to the on position, the low beams turn off. (Whereas, the drl mode is canceled or bypassed by the switch, but fails to go into 100% power to the low beams). Is this a failure of the switch, or the drl relay?
In the picture, there is mention of a "tan" wire.
There is a tan wire as part of the wiring harness to the switch.
The tan wire is discolored (brown/burnt) at the point where it ends within the harness (approx. 1/2")
What may have caused this?
Where does this tan wire come from/go to?

Thanks for your answer(s)