I ran mine to a relay by the fuse box then through the ebrake hole into the cab to a switch.

This is an old pic, but the bottom one was the cutout,

 

heres a quick how to i did on silvss.com for my truck

hope it helps

http://www.SilveradoSS.com/forums/in...howtopic=63464

 

yall think of nice places for switches! lol......i have a hidden place where mine will be going i got a full center console and took the little radio/ac thing out of the back and it left a perfect little cubby for switches lol

 

i know this is an old thread but how long of a wiring harness was needed to run this

 

if you buy a dmh cutout, it comes with the switch and wiring. its 8-10ft long if i remember correctly

 

yeah its a pretty long harness. should do just fine

 

IIRC, when I ordered mine they asked how long of a harness that I required...