this may be a dumb question but bear with me. i have two fog lights on my front bumper of which i mounted and wired with a relay and did all that stuff to make it safe. i want to add some roof lights now and i was wondering if i could just splice the power wire to the switch i have now into three to power all the switches or will this screw up the circuit? the reason i ask to do this is instead of having three small voltage power wires go to the same exact spot why not just conncect them all into the same one? (i know each pair of light will need its own power wire) ( i also plan on running three different relays for each pair of lights)

thanks,
joma

ps. any opinions on these? : http://www.walmart.com/ip/Blazer-100...Light/15111226

Wouldn't it be easier to get a bigger relay and run them all to one relay with one switch? or I guess your way would work.

i want to at least have the fog separate from the roof lights but i could just run one big relay for the roof lights. hmmm

that will work fine, the toggle switch is just signal for the relays to ingage there is next to no amperage draw on that circuit. I prefer to have bumper lights and roof lights on different switches though. but if you don't care about that, one switch will work if wired up the way you specified.

if i wanted to wire the roof rack lights all two one switch what gauge wire will i need for the whole set up or how can i determine this?

At least 12 gauge I believe

If your going to be running multiple lights on different switches and all that (like me) you could run a LGW (large gauge wire) like an amp power wire 8-6 gauge to a mounting point with multiple connections to the inside of the jeep and run your other positive wires from there. It's easier and keeps from having multiple wires running through the firewall or under the jeep. Just an idea.

Wattage really needs to be known before suggesting wire size. My lights on my rack are wired with 8g

http://shop.advanceautoparts.com/web...A%7CGRP2044___

would this kit be able to work all four 100watt lights? with all the lights running it should only be about 17 amps so shouldnt the 40 amp relay be fine?
(im no electrician so thats why im asking lol)

Four 100w lights is about 33.3 amps so your still good

All the wires should be thick enough?

Personally id use 10ga for the roof lights

+1. 10GA is the way to go!

24 actually

400÷12?