Positive or negative switching?

Hi guys,

For my my thread titled: Help needed (http://www.automotiveforums.com/vbulletin/showthread.php?t=4164), I need to know if the GMC Sierra 1992 does use positive or negative switching?

i assume your talking about the headlights and taillights. both are positive switching. taillights work off the small brown wire at the switch. if i remember right the lowbeam headlights are light green and the highbeams are dark green but i could be wrong. have fun