[Gregski]

guys lets talk headlight for a minute, I like to understand how to test them when there is a problem and not just run out and buy a replacement, but I don't get how they work

here is how they are wired, they each have three prongs so if we look at them from the back the left most vertical prong has black wires going to it, so we assume that is negative, opposite that prong is another vertical prong on the right this one has light green wires going to it, and then there is a horizontal prong above with light brown wires going to it

when I took a test light to the wiring harness here were my test results even on the working side (cause only driver side low beam does not work)

Black & Green = light on

Black & Brown = no light

So do they work such that when Black and Green is on then that's low beams and when Black and Brown is on then that's high beams for example? Or is high beams when all three are on?