Fog light wiring

[BDPJR]

There I am tearing up the dash looking for the headlight wire to clip my fog light switch to... there's about 16 wires to choose from and I know it's not the black one... or is it? Any ideas folks?

[BDPJR]

I'm installing a Delta Fog kit and the instructions show the three wires from the switch: ground, source,(85 on the relay), and headlight wire. It says verbatim: "red wire tap into headlight wire lead with snap lock connector". I've done fog/off road lights many times on older trucks and cars, but the green headlight harness on the Hummer has about 16 wires.
I was hoping to tap into the fuse box under the hood and the 25 amp fuse for the sunroof,( I don't have one), didn't show any power with or without the ignition on. The links you sent show a SEO ACCY that I can use; I over looked that - thanks. I will read the rest of the links you sent and see if that shows me the answer. Tonight I will scan these Delta instructions and post them for you to look at.
Thanks, Brian

[BDPJR]

I've been doing the multimeter dance, but plan to call the dealer when they open in a few hours. Thanks.

[HUMTECH]

FIGURE Headlamp Controls, Switches, Ambient Light Sensor(c)

[BDPJR]

Humtech, First - nice avatar, second thanks for the wire diagram; it will help. I wish I could get my hands on a repair manual either on DVD or paper form. Thanks, Brian