[cstanley]

a quick google gave me this from another website:
"Yes, after a long day proving to my 34 year old body that it can still bend like a 3 year old (at least until tomorrow when the stiffness sets in), I succeeded in wiring in a kill switch using lighter as the switch.

I wanted to share the story because there were a few learnings along the way, so hopefully you won't make the same mistakes.
Executive summary:

Pros:

* Easy and works well.
* Cheap - costs about $15 Cdn. - Cost me $25, but you don't have to make that mistake :-) .

Cons:

* Working on the wiring underneath the dash is a real pain. As a 6 footer I did it, but it was painful. On the positive side I could look for work as a contorionist at a circus now.


Why I felt I needed a Kill Switch:

I park in the river valley, ten minutes from work. There's not many homes near by, only abandon cars of cheap parkers like myself. I have known two friends who have had their car stolen from the valley. The cops told one of them to pull the ignition fuse each morning to prevent another theft. Yeah, that'd be handy <g>...

I decided to follow in Keith Tanner's footsteps and wire in a kill switch. Keith chose to locate a switch in the lockable console, but I wanted it a little handier. The lighter is only 3 inches from the ignition - can't get much handier than that. Now to start the car you have to know you need to push in the lighter.

I don't smoke, nor do I use a radar detector, so I didn't have much need for the lighter. If I decide I want to plug in an accessory it's pretty easy to pick up an accessory plug at "Canajun Tire' and wire it up.

Here's the 7 easy steps to wire in the lighter as a kill switch.
Step One:

Buy small package of 10 guage wire. You'll need about 4 feet but will undoubtably end up buying about 25 feet.

Buy small package of 18 guage wire. Just about any wire will do, but this lighter guage stuff is easier to work with. You only need about 3 feet. Even half a cord of lamp cord will do.

Buy package of 10-12 guage butt connectors. The type you crimp on to connect one bare wire end to another.

Buy 12 volt, single pole relay, 30 amp or so. BIG HINT: Don't buy a 70 amp relay - it won't work... trust me :-) I found one at Radio Shack for $10.

Buy package of push together 1/4" connectors (plug in type - type you can insert and detach). At least that's what my relay needed. In other words, buy something to connect wires to your relay.
Step Two:

Prepare the car and your back. Remove driver seat, plastic chunk under steering column (two phillips screws then pull it downward from the screw end - gently), and touch your toes 30 times (ok, its optional, but all the pros do it). There's not much room to work under here. My arms are still sore. Remove ground from battery... just to be safe.
Step Three:

Identify the wires running through the clutch switch. The ignition circuit requires both the key to be on 'start', and the clutch to be depressed (sorry, I have a five speed; if you have an automatic this won't apply). See before and after pics below. Careful, there's two switches on your clutch. One for the criuse control which is there whether or not you have cruise control. The one you want is near the floor. The clutch needs to be pushed down to the floor to empower the switch. There's two green wires wrapped together from the switch which route above the fuse box and to a harness plug. You can disconnect the plug to give you a bit more room to work. The wires are sort of clipped up above the fuse box, but you can feel the clip, and unclip it to give you more room to work. You will know you have the right wires by disconnecting the harness plug and trying to start the car - remember to connect battery ground if you choose to do this test.
Step Four:

Cut into ONE of the wires and use butt connectors to crimp on two two foot pieces of 10 guage wire - one to each end of cut. Note, car won't start right now, so don't do this right before you have to take kids to swimming lessons...
Step Five:

Connect 10 guage wires to Relay. The relay will identify four connectors. Two will show they are for a open/close contact. This is the one you want. The contacts are open until current is passed across the other two connectors. Now before you crimp on connectors to connect the heavy wires to the relay, you need to subdivide off some ignition circuit's power to go to one of the other two connectors. You use the ignition circuit's power to _also_ go through your switch (lighter). You could solder a wire across the two connectors, or do as I did and using a short two inch piece of wire jumper between them. (see diagram)
Step Six:

Connect Lighter to relay. Pull out your lighter. If you pull it out sort of at an angle it will pull out the socket and all. Gently now. I don't want to be held responsible for broken dash. Or, reach around the back and push the socket out. There's two wires connected to it: power and ground. The ground is connected to the casing of the lighter socket, and the power is connected to the screw in the centre of the casing. There is a black plastic harness holding both wires so they plug into the lighter as one. Now however you want to do it, the goal is to disconnect the 12 volt source, and run a light guage wire from the relay to the positive (power) connector on the lighter, and have the power pass through the lighter and out the ground. I cut into the ground. I crimped on a 1/4" plug in connector, and folded the wiring plug and power wire back,and taped them up. Now I had the ground connected to the lighter, and a new lead from the relay to the lighter's power lead (the centre one) (Yes! We do spell centre that way in Canada).
Step 7:

Find somewhere under your dash to mount your relay. On my car there was a conventiently located bracket sitting there unused. The relay will have a hole for mounting it, so it should be pretty easy. Now tape up your work to secure it all, and help it blend into the naturally occurring darkness under the dash. Push the clutch switch wiring back up on top of the fuse box. Hopefully your splice will be well hidden by the fusebox. Reassemble car; seat and underdash piece of shrouding.

Oh yeah! Test it before putting it all back. I figure you'll do that, but I figured I'd mention it. You'll have to make sure you reconnect your battery, or else you're sure to be dissapointed :-)

If you try to run the clutch switch wires directly to the lighter (i.e. no relay) you will find it won't work. There's too much resistance in the lighter. That's why the relay is used. If you really didn't want to use the relay you could solder some wire into the lighter to bypass the lighter coil, but one such previous attempt resulted in the wire coming loose after it got 'heated' up repeatedly.

The first relay I bought from an electronics specialty house was a 70 amp. It wouldn't work, so make sure you get a lower rated relay.

So, now I can sit at my desk at work, looking down upon my car about 400 yards (and five minutes if you run) away, and feel secure.... and hope I don't run across a thief who smokes and decides to light up before jammin my ignition switch :-)

Good luck. Feel free to write if you have any questions..."