My 2008 H3 Alpha Hummer passenger low beam headlight suddenly stopped working. New bulb, relays, fuses and headlight connector. The passenger high beam works. The drivers hi/lo beams both work. Found the passenger headlight dark blue/low beam wire that is meant to be wired to the new headlight bulb connector is not grounded. The new connector is AC Delco which the dealership printed out the correct wiring positions for me. I did a ground test to assure it is the low beam wire that is not grounded. Any idea where this ground wire is located?

 

 

I was able to find this. I’m assuming it’s located behind the radiator? On your attachment would the location be #19?