So i have an electrical question, so i have led's behind my grill and where i live they are illegal to have in the color i have and where i have them, i have them currently wired up to my headlights and want to be able to toggle them on and off, to avoid issues with cops, unlike now where they are stuck on when my headlights are on, i haven't looked into it much yet, the idea just kinda popped into my head recently and i have been contemplating it for a little bit now, but i don't want to get the wrong part for the job, seeing as this could be a very cosmetically bad failure if i do this wrong

 

Easiest is to have a dedicated switch for them, wired to something that takes power only when key is in ACC

 

ok, but how would i go about running wire from the front of my bay to the cabin? like i said i haven't looked to deeply into this yet

 

Being a Jeep owner, we Jeepers do this all the time. What you'll want to do is get a standard 30A or so auto relay. The Control side gets the accessory power +12V of your choice (tapping off of cig lighters is great for this) running to that to the #87 on the relay, a wire from #85 spot on the relay to a standard toggle switch cleanly mounted on your dashboard somewhere accessible (A knockout is best) and run a wire from the toggle switch to ground (if you want a lighted switch you need more wires and am not going in to that).

That is circuit one: Acc. +12V to relay87/85 to SPST switch to ground

Then you run a wire straight from your battery - through an appropriate fuse (15A typically, less if your lighting isn't heavy -LED) to the 30 of the relay and then a wire from 86 to your lights and then your ligths go to ground, which probably already exists.

Circuit 2: Batt +12V to fuse to 30 on relay; from 86 on relay to lights to ground.

To your questions about the wire through the firewall... Search for a way to do it, run a hanger or stiff wire through the hole and then pull your wire back through that.
You can do the project with either 1 or two wires going through the firewall, depends on where you pick up the access +12V I would leave the relay in the engine bay somehow waterproofed.

Now your lights can be turned off at will and come one and off with the car if the switch is on so you don't kill your battery.

Here is a diagram:
http://www.zoopedup.com/blogs/wiring...-27-oct-2009-8

FWIW, here are all the lights on my Jeep:



A little ghetto for a maxima but I put all my relays in a waterproof otterbox box:


With some quick connect plugs it pulls out but fits in the engine bay nicely:

 

My switch was for a light in the rear. Ghetto but simplistic.. I ran two wires to the light and the wires met at the switch. Solder an inline fuse and done. I mounted my switch in the blank button where tcs would be if I had it. Dremels your best friend.

 

You could wire the toggle switch to the cig lighter and you can get in to the cabin from the engine bay from the driver side wheel well

 

Post more pictures of that yellow monster