View Full Version : "Kill" switch for manual transmission TJ/LJ

11-29-2009, 15:36
Only works on MANUAL transmissions with Clutch Pedal Position Switch. I did mine on an '04 TJ with NV3550.

Why it works:

"The clutch pedal position switch is used to prevent starter motor engagement unless the clutch pedal is depressed" (pg 314-315 TJ FSM)

Therefore, the theory is if you break the connection via a switch, no power goes to the starter motor hence no engine crank.


-Roll of wire. I used a roll of accessory power wire from Pep Boys.
-2 position switch of choice. Smaller the better (easier to conceal)
-Connectors of choice
-Electrical tape
-Wire Strippers

1. Designate a concealed site for your switch. Pick anywhere out of sight and attempt to place it where it looks natural for your hand to graze across. You don't want someone spotting your rig to see that you're obviously going by the gas filler tube on the outside to flip a switch (exaggerated stupidity, but helps get the point across).

2. Cut two lengths of wire that you bought at your parts store, running the length from up under the dash by the firewall to the site of the switch. Keep in mind that you need to allow yourself the amount needed to conceal the wires. When I did it, I gave myself an extra foot or two and cut at the end. Strip both ends.

3. Look under the dash at the clutch pedal. If you run your hand up the pedal itself, you should feel a compression spring with a two way wire going into it. It should be the only wire touching your clutch pedal switch assembly. It's technically called the "Clutch Pedal Position Switch" and can be found on pages 314-315 of the TJ FSM.

4. Cut the wire for the CPPS as close to the halfway mark as possible to allow yourself as much working length possible. Strip both ends of the CPPS wire.

5. Using the store bought wire and given connectors, connect wire from CPPS to the switch. Using your second length, connect wires from switch back to the main harness. In effect, all that should've technically been done is extending the wire to your switch site.

6. Test switch. In one position, the starter motor should not engage. In the second position, the starter motor should engage and crank the engine.

7. Re-test switch.

8. Test switch again.

9. Once you've established that your switch works, clean your connections and cover them in your preferred method. I used electrical tape. Conceal all wires and cut/drill switch into final resting position. As you do this, you can cut your excess wire leading to your switch.


11-29-2009, 16:38
Or... Put a fuse in spot 20....

That's what I did with mine a while ago.

11-29-2009, 17:42
Does it require placing and removing everytime?

11-29-2009, 18:05
I leave mine in there ALL the time...


11-29-2009, 18:11
Lmao. That's the opposite of what I'm saying. That's to bypass it so you don't have to compress the clutch to start. The kill switch will make it so that it won't work at all. You can compress the clutch or not compress the clutch and it won't start.

If the perp happens to be carrying a 20v fuse in his pocket or whatever and knows the trick then you're ****ed I guess. haha

11-29-2009, 18:19
Guess I should have read the ENTIRE post...

To think... I was just picking on a few guys on another forum for NOT reading the ENTIRE thing!!!

11-29-2009, 19:04
funny. no sweat.

12-02-2009, 01:53
Anything about Fuel tank kill switch I believe?