NEED HELP WITH KILL SWITCH on a VW Jetta

Go to the Lemons store and buy this switch
http://store.24hoursoflemons.com/produc … switch.htm

Now follow this diagram (Lemons store version uses 1 and 2, while other sources use Z and W, the one you buy will have the right diagram)

Basically, on one side you want the battery positive terminal. On the other you want the positive feed to the rest of the car, the starter, the alternator, etc.

You then jumper that car side to the set of terminals labeled 1 (or W). On the other side of 1 (or W) you connect a large resistor that goes to ground. This set of terminals is disconnected when the switch is on. When you flip it off they connect and any power from the alternator is allowed to bleed off as the engine spins down.

For the set of terminals labeled 2 (or Z) find the wire that feeds 12V to your ignition switch. Usually a red wire. Cut it, and run the cut halves to these terminals. When the switch is on, they are connected. When you flip the switch they are disconnected and it's like turning your key off. The engine will stop.

I agree with not flipping the coil, which is why I said to instead switch the power wire to the ignition switch. Then when you flip the switch it's like turning the key off. This should do the same thing as you described controlling the alternator.

Wiring as I outlined above is the most thorough approach. First it isolates the battery from the rest of the system. That's good. Second it ensures the car turns off, since it mimics turning the key off. Third it allows any power from the alternator to dissipate so nothing is damaged. And then once the engine is spun down there is no more power from the alternator and you have truly isolated the chassis from power sources.

I'm wiring in a kill switch to a more modern engine right now that has individual coil packs on each plug. Part of the reason I go with switching the power feed to the ignition switch (aka where they key goes). If done how I outlined, it will work and be tech approved.

I agree there are a few ways to do it. Several make me nervous, like leaving it so the alternator is still hot with the battery after the switch is flipped. And oh god placement. Please don't ask about placement.

Vw/Audi's have self exciting alternators. Switching the battery light wire will do nothing top stop the alternator from charging. If you try it that way and cut the alternator from the battery without a resistor to dump the power through the alternator will take a hit every time you switch it off with the kill switch.

You can use the switch pictured to interrupt power to the coil, injectors, or ecu. You can figure out which fuse you can pull from the fuse box to kill the engine reliably and repeatedly. Then use the kill switch to interrupt that circuit. When you find it, try to wait for the cooling fan to go on and pull the fuse. If it dies instantly you should be good.

Don't neglect the resistor wiring. It saves your alternator.