The access caps and bulbs are removed. The yellow wire powers the low beam bulb and black is the ground.

Note, like Georgeandkira says, the plastic insulator that held the yellow and black wires side=by-side is long gone - no big deal.

Check that the female spade connectors on each wire are firmly attached (all strands) and not all rusty and corroded. Re-terminate them if needed. You may have to get new terminals. I believe the dealer sells a new bulb connector with pig tails.

Then connect the bulb and apply 12v power and a ground path to the main connector on the outside of the headlight assembly as I have marked on the photo. See if the bulb burns continuously.

No? = Problem is in headlight assembly
Yes?= Headlight is good

Then connect the headlight to the car's wire harness. Now see if the bulb burns continuously.

No? = Problem is in the car's wiring
Yes?= Miller time.