2004 Silverado Roof Warning Light

[fireman2004]

I have a 2004 Silverado 2500HD extended cab. On the dash board there is a button for your typical roof mounted yellow "gumball" light. I would like to know where GM placed the roughed in wires that correspond to this button. I am planning on hooking up a yellow light for plowing. I removed the 3rd brake light lense but do not see any wires in there.

[3mikeman]

On my 99 it was behind the headliner just reach up above the drivers side there is a pigtail in there towards the middle.