KILL SWITCH, AGAIN

#1

I know, this is a dead horse, but I went all the way back to 2005, and couldn’t find what I’m looking for.
I guess you guys don’t like to post pics.
Can you please post pics of your kill switch installed, and external pulling handle?
A wiring diagram would be great as well, I’m more of a "graphic" kind of guy, that’s why I don’t like the Bently manual.
I’ve seen two different places for the switch, on the driver side vent, and cage. I like the first.

#2

OK, now I’m very confused.
I searched the web and I see a lot of cars with the kill switch in the trunk, with some type of pull handle. My guess is that’s only for NHRA kind of racing, right?
HEEEEELP!!:woohoo:

#3

I’ll take some pic of mine tomorrow and post or email them to you.

#4

You can check out Brain’s installation in the gallery. -->#105 blue Spec e30

#5

Pull Cables can be made up with bicycle cable casing and cable for about $10.00 in parts.

You can get crimp on ends at any marine supply store ( my local west marine has them and cable that are marine grade) and most hardware stores.

Anchor each end of the cable housing in an appropriate spot, making sure the angle of pull is how you want it, then feed cable through it.

The cable housing ends are anchored easiest by simply drilling a hole (big enough for the cable and small enough that the housing won’t slip through) in a bracket near where you want the cable to go.

Make sure you run big curves in the cable and the shortest possible route.

For a pull handle just loop the end of the cable after you slipped it through a tube or scrap piece of cable housing.

Yeah I know you are visual and this is not. For an example Mike D might be able to take pics of his car…as that is where an example of these home made cables can be found.

#6

I haven’t done mine in my new se30 car yet, but in my e30 M3, the kill switch is in the trunk, with a cable/red pull handle that I hang outside the trunk while racing. It is a street/race car so it is nice to not have the kill switch exposed where kids can play with it.

In my M3, (which should be the same as the 325, battery-wise), there are two wires running from the +ve battery terminal - a large one and a small one. My kill switch has large terminals and small terminals. The large wire goes to larger terminals and the small wire is interrupted by the small terminals.

With your car running, flipping the kill switch needs to kill the engine and this wiring achieves that.
cheers,
bruce

BETO wrote:

[quote]OK, now I’m very confused.
I searched the web and I see a lot of cars with the kill switch in the trunk, with some type of pull handle. My guess is that’s only for NHRA kind of racing, right?
HEEEEELP!!:woohoo:[/quote]

#7

Make sure you have a shunt on the kill switch or you will blow up your alternator too!!!

#8

email sent

#9

DP motorwerks in VA Beach did mine. Here’s a pic that I took last night. Unfortunately, it wasn’t just of the kill switch so it doesn’t show the pull handle in the pic but it’s there.

#10

Thank you guys, you are great help.
In conclusion, I can install the kill switch in the trunk with the pull handle hanging back there for the crew, I don’t need the switch inside the cabin, as long as it’s somewhere in the car.
I’ll use the hand brake cable casing and cable.

#11

So, I searched and searched all over on the damn kill switch wiring diagram and placement. Here is the plan. Mount on the passenger black plastic piece below the windshield.

I am posting here for 2 reasons -

  1. To confirm it is 100% correct
  2. To pave the road for those that try to do it later.

Note: You need to test this thing 2 ways…

  1. Will it prevent the car from starting (easy)
  2. Will it "kill" the car when running safely (harder)

Any feedback is appreciated!

John

#12

And the related diagram for the ignition tie in

#13

if you look at your battery in the trunk, there are two wires coming off the positive terminal. Both of these wires need to be interrupted by two of the poles on the kill switch in our cars. No need to hunt for the ignition switch/coil wire. On my e30 m3 racecar, I do not have a shunt resistor for the alternator and it is fine. I have read lots of others do not use one either.
cheers,
bruce

#14

leggwork wrote:

[quote]if you look at your battery in the trunk, there are two wires coming off the positive terminal. Both of these wires need to be interrupted by two of the poles on the kill switch in our cars. No need to hunt for the ignition switch/coil wire. On my e30 m3 racecar, I do not have a shunt resistor for the alternator and it is fine. I have read lots of others do not use one either.
cheers,
bruce[/quote]

Bruce,

Thanks, but I have a question…

I don’t have the switch installed, but, to test, I started the car, and pulled the 2 cables you are talking about off the (+) terminal of the battery. The car continued to run! I assume it is running off the alternator. Don’t we need the ignition wire in the picture to actually "kill" the engine? When your car is running, and you turn the switch, does the car die?

Thanks - I started this conversation on bimmerforums - http://forums.bimmerforums.com/forum/showthread.php?p=10342153#post10342153
if that helps with background…

And I appreciate the help on this…

#15

It’s very easy to interrupt the positive lead to the coil to kill the engine when it’s running. I hate all things electrical and was still able to wire this at 2 AM in 15 minutes before heading off to competition school.

Sasha

#16

Good call, Sasha. I modified the diagram accordingly (allowing wiring drom the coil or the ignition), and put the distribution block in.

Look good?

#17

yes, my car definitely dies.
When you tried pulling both wires off the battery terminal, were the two wires still connected together - perhaps there is a circuit from the large wire to the small wire that needs to be interrupted (which happens if you wire those wires through two poles of a cutoff switch.
thanks,
bruce

jblack wrote:

[quote]leggwork wrote:

[quote]if you look at your battery in the trunk, there are two wires coming off the positive terminal. Both of these wires need to be interrupted by two of the poles on the kill switch in our cars. No need to hunt for the ignition switch/coil wire. On my e30 m3 racecar, I do not have a shunt resistor for the alternator and it is fine. I have read lots of others do not use one either.
cheers,
bruce[/quote]

Bruce,

Thanks, but I have a question…

I don’t have the switch installed, but, to test, I started the car, and pulled the 2 cables you are talking about off the (+) terminal of the battery. The car continued to run! I assume it is running off the alternator. Don’t we need the ignition wire in the picture to actually "kill" the engine? When your car is running, and you turn the switch, does the car die?

Thanks - I started this conversation on bimmerforums - http://forums.bimmerforums.com/forum/showthread.php?p=10342153#post10342153
if that helps with background…

And I appreciate the help on this…[/quote]

#18

Good point. I see what you mean - you are really interrupting 2 circuts (which is what I thought I was doing when I pulled the wires off the battery, but I wasn’t) - the alternator circuit and the battery circuit. I’m going to test that out tonight.

Thanks Bruce

#19

Bruce is 100% right. Disconnect the 2 wires from the battery, and separate them and all is off and dead and isolated. No need to involve the coil or ignition. Optionally, you can add the alternator protection - the 6 pole switches support it, or I guess you could use it for fire suppression systems.

Here is the final diagram for all your perusal. Thanks to all!

#20

John and Bruce - I believe you have come up with a much better solution to this issue - at least for the e30. I followed the instructions with the switch - doing the alternator loop/coil interuption, but this solution looks much more logical. I believe many of us have done the textbook version thinking the kill switch killed all power. It clearly does not leaving the power going to the alternator power block under the hood when the kill switch is off. I always disconnect the negative terminal from the battery as an added precaution when working under the hood, but it I do the wiring scheme you have come up with, you shouldn’t have to.
Thanks, Ed