Kill Switch

[backformore]

OK. I've just bought my first VW race car. It is an ITC Scirocco II (1.7). Now I begin the fun(?) of learning a new makes unique elements as well as figuring out what needs to be changed on the car to make it comfortable and legal (new belts etc.).

One item to address is that the kill switch disconnects the battery, but does not stop the car if it's running.

The switch is a simple 2 terminal part. What is the best way to wire it to kill the car and address all the other safety issues? Can it be done with this switch or do I need one with aux circuits etc?

Thanks for the help. I'm sure this will not be my last question as I begin to unravel the mysteries of VW.

[Conover]

You should be able to do it with that switch. What works on our electronic injection car may not necessarily work for you though. we run the battery + to the switch, and nothing else to the battery. Then take the other side of the switch and run it down to the starter terminal. we then pick up our other power leads at the starter terminal, Alternator, fuse box, etc. all going to the starter.
It works perfect on our car, kills the computer, fuel pump etc. and I think It would work on yours too.

[kbee00]

In every car I've owned - from FF's to EP cars - the kill switch was used to disconnect the negative side of the battery from the chassis (ground). I can't see any reason why a VW would be different. Is there something going on here I don't know about with these cars?

Loren

[Conover]

I tried disconnecting the negative side, the car keeps running. :o
Disconnect the positive side and it shut right off! :D
I would have preferred to have the kill switch on the negative side, but it just didn't work, the alt is case grounded, the ecu grounds are on the block, etc.
just way easier to kill the + ;)

[shwah]

Do some quick research to keep from frying your alternator when you kill the field with that switch. If you wire it right you won't have to replace the alternator just because you flipped the kill switch (won't go every time, but it just takes once).

I don't recall the details off my head, but I am sure they are on the interweb.

[kbee00]

conover - bottom line is that if the only thing connected to your battery neg terminal is the cable leading to the kill switch and the other side of the kill switch is connected to the chassis - there is no way for any current to get to anything. I'm guessing that there is another wire (or more) that is running from the neg terminal on the battery to someplace else. No car will run without a battery (not modern cars anyway) so you take the battery out of the loop - ta da! - no current. End of story. And you won't have any worries of frying your alternator either. Now if someone stuffed a magneto into your car when you weren't looking - welllll, then that's another story.... :D

good luck with your endeavor.

Loren
Yellow ITB Golf

[Conover]

Nope, we pulled the negative terminal off of the battery with the car running and it continued to run. . .
Nothing was hooked up to the negative side at all. I'll go try it again, if you want, but you still wont believe me.

[Knestis]

I was there.

Cameron asked why we didn't put the switch in the (-) side and the only answer I had (old guy syndrome) is "that's the way we've always done it." He pulled the terminal off the negative side and - much to both of our surprise - it kept right on going.

We used to have to switch the alternator off with the second, smaller set of poles on the switch but have rearranged the major hot leads so that everything connects at the alternator rather than at the battery +. The first time I installed it, it took me a while to get this worked out, then I very cleverly thwarted those efforts when i installed the enduro lights the first time: I ran the primary power (the relay switched side) to the battery itself, and we discovered the hard way that turning off the switch no longer isolated the battery from the car. Sparkity-spark.

K

[JamesB]

at least there was no poof, boom, or kablam. So I cassify that as a small oopsie.

I think if I ever setup a car for enduros I would actually mount a distribution block like the big stereo guys do and route the proper gauges to the starter, altanator, enduro lights and anything else that needs direct battery draw back to the switch, then switch to battery. Then if I have to add something in the engine bay for direct battery I can do so easilly.

[kbee00]

conover - that is the strangest thing - I certainly stand corrected. Now I'm gonna get a headache trying to figure out why your car would do such a thing. Frankly, I'm not as familiar with installing a kill switch in a rather stock production car. I guess as long as the motor is turning, the alternator is continuing to supply current to the "engine management" system. I wonder how long that would go on - you wanna test that one for me :D No, didn't think so....

Loren

Yellow ITB Golf