Alright so I have read a lot of threads on wiring a hidden kill switch into my 99 XJ and I can't seem to find a solid answer on where the easiest place to do so is. I know super basic electrical, so if someone could break it down into simple terms, that would be great. It doesnt really matter if it's a fuel pump cut-off or an ignition cut-off, I just want something that without being flipped, the Jeep will not start. I am not picky on where it is located either as I can extend it out. Any advice would be greatly appreciated. Thank you.

 

I would argue that the fuel cut off would be easier to hide and thus, more secure. You need a relay, some wire and a switch. The switch needs to be hidden. There are magnetic reed switches that you can use, that are "activated" in the presence of a magnetic field. This allows the switch to be located behind a piece of plastic for example. The problem is if that magnet moves while you are driving, your car dies.

Here's how you wire it.

 

to avoid the reed switch deactivating problem, you need to just use the reed switch to activate a DPDT relay. that way the reed switch is not being relied on to keep the jeep running, just to start it.

 

Awesome! Thank you for the replies guys. I do have one question though. Is it necessary to have the relay? After reading your suggestions, I did a little more research about wiring one to the fuel pump and it seems like a lot of people just used the fuel pump wire under the driver's side, spliced into it and installed a properly-rated fuse. Would this work?

 

Work? Yeah. Is it right? No. The switch can't pass current like a relay can. If you put the switch in and it isn't rated right it will burn and start a fire. If the switch is too big, its hard to hide.

 

Alright well then I'll definitely be using a relay. Like I said, I'm not the brightest when it comes to any kind of DC wiring. I will probably just use a regular switch and hide it really well. So if I located the one wire that goes under the driver's side kick panel, will that one wire be the wire from the fuel pump power source and to the fuel pump? In other words, how many different wires will I need to locate? Sorry to sound so dumb. Thank you again.

 

You just need to find the hot wire to the fuel pump.

 

I've ran "kill" switches in several cars. A 74 camaro, you had to depress the dimmer switch on the floor to start it, an 87 nissan pick up, you had to turn on the headlights to start it. My 01 blazer had a factory kill switch, if the cigarette lighter wasn't plugged in, it wouldn't start.