I did a little different set up for my tahoe. I actually wired my existing fogs to run while my DRLs on. I then installed an aftermarket set of fogs on my Westin Bull Bar, which I control with the factory fog light switch. No extra relays or anything were needed. Just cut the wires from the back of the fogs and spliced into the DRLs wires. Then ran new wire from the existing fog light wiring to the new fogs. Took about 45 mins total.