Tuesday, April 21, 2009

11. DIY - Start Button & Kill Switch

As I prommised - here's a little DIY for installing a Start Button, Battery Cut-Off Switch and ignition Switches into your BMW E36. The car I'm working on is a earley European 325.  There are some chances that it's not completley like yours. And, by-the-way, I'm not responsible for any damage you make on your car.

My setup eliminates the key completley. I have two switches:

  • ACC - the 1st position of the key
  • IGNITION - the 2nd position of the key

I have a Start Button, and a Kill Switch.

To start the car, there's no need to set the ACC to on. Since I'm building a 'race' car, I don't have any music in the car. But if you plan on putting this in a daily driver, you could find this switch usefull, since it controls power distribution to your head unit.

Fasten your seatbelts! We're taking off!

What do we need?

  1. On/Off Switch [x2]
  2. Start Button [x1]
  3. Kill Switch [x1]
  4. Wire
  5. Terminal connectors


  1. Wire cutters
  2. Wire strippers
  3. Wire crimpers
  4. Isolation tape
  5. Plasma torch

(yes, #5 is a joke)

Ok, so what's the procedure? First take off any plastic you have under the steering column. Then find the wires comming out of the ignition switch located on the left side of the column. (The ignition lock is on the right) Follow the wires until you come to a connector. It should be attached to the steering column with a plasic holder. Disconnect the connector, and then about half-way to the ignition switch cut the wires. (Make sure there are red, green, black+yellow & purple wires there).

Here's a drawing:

  1. Ignition switch
  2. Connector

Blue line marks the cut.

Ok, now, here's how the new components go in:

A - Start Button
B - ON/OFF Switches
C - Kill Switch

Be sure you isolate every connection! Stick the connector back where it was, and try it! :)

Probably, it would be a good idea to put a couple of circuit-breakers (fuses) in there... but, hey, it's up to you.

Hope this helps. If you have any questions, do ask.

A couple of photos from my car:

Switches, wires, pliers... :)

Ah! Here are the connectors (after disconnecting)

This is the interesting bit.

Spaghetti, anyone?

In a day or two, I'll post a DIY for the dash panel that will hold my switches :)

A couple of cool things...

Start button for $33.11!

Kill switch for $14.95!


  1. just wonderin if you could explain why you hve 2 on of switchs i get one is for acc what the second fo send the kill isnt connected to the start


  2. I used two switches, because I don't have a key anymore. When you use a key, you turn it in three steps: the first step (acc) usually shows the service indicator and miles on the dashboard. It also provides power to accessories, like the stereo. The second step of the key (ignition) usually lights up the battery and oil lights on the dashboard, and provides power to heater controls, power windows, and other electrical stuff. The third step of the key (start) starts the engine.
    Since I don't have a key in my car, I wanted to simulate the key with two switches and a push button. Switches for first two steps, push button for the third (final) step.

    To turn the car off, you need to turn off the ignition. (It's the same with a key.) In my case, that's the switch #2.

    Please note, that I have rewired the whole start button/kill switch assembly. Check it out here:

    Well, the only difference is that, now, the kill-switch cuts off the power distribution (red wire).

    If you like, tell me what kind of setup are you looking for, and I'll write a DIY for your specific needs.

    Hope this helps &
    Thank you for your question!


  3. there is 3 more little wire at the connector, (originally) what wire is it? We don't use this cable anymore? My E36 year 97 with immobiliser.

  4. I cut those 3 little wires, and isolated them.
    I did not connect them.

    Since you have the immobilizer, you need the key in your lock to start the car. But you still can put the start button and kill switch in. The only restriction is that you will have to turn the key to the second position, and then use the start button to turn on your engine. I'll draw two possible diagrams for your setup tomorrow. (I'm putting my kids to bed now...) :o)

  5. I'm about to get a 96 E36 with immobilizer, can I have both switches and start button while just having the key in the ignition? As in, have the key positions operated by the switches and have the key in there only to allow for the immobilzer?

  6. Yes, I think you can do that.
    I was actually thinking of doing the same, with a little bonus - I plan on moving the ignition lock from the steering column to the glove-box compartment :)

  7. hi, i did this process in my BMW 92 325i 5 months ago and eventually i been having a problem. the car starts fine, but i can't start the car for more the 3,4 or 5 times a day it seems that the switch overheats then i have to wait for around 2 hours to it cool down to start the car again, I'm not sure what is the problem could be the wires that are to thin? or the switch?? thank you.

  8. Hi kio_jose_jgm!

    I think that your suspicion about thin wires and/or weak switch is correct. My best guess is, that adding a relay would solve your problems...

    I remember that someone did it with a relay, but I cant find the web page right now... I'll google it, and as soon as I find it, I'll post the link here.


  9. my ignition barrell broke on my bmw compact 95, so what i did was made a replacement ignition swicth near the gear stick added a start up switch button at side of it, works great, all i do is put the bmw key in old barrell for immobilizer then turn the electrics on with the the new ignition switch and press engine start button it works ace, bmw wanted 500 for new barrell and keys and locks on doors changing this set up cost me about 25, never done owt like this before, anyone got same problem u can get intouch leeagilbert@hotmail.co.uk, it looks sporty and fires up everytime

  10. Got a question about the 2nd diagram. The red wire, do you need to split it up 3 times? (if using that amount of switches) And do you have a detailed pic of them splitting? I'm a bit of a newbie but if I see a pic I can work it out! :D
    For the rest this is a great DIY!


  11. Yes, you have to split the red wire 3 times.
    Sorry, I don't really have any better pictures.

    I guess I'll be doing this all over again, so maybe then I'll have some better pictures.

  12. Hey man i have a bmw 528i from 2000 so it has an immobilizer and to be honest I'm not that good with cars even though i did set up a push start for my friend's honda I was wondering if you could draw me up a diagram for how to do it with my car but with out the kill switch (unless you think i really need it), it would be much appreciated.


  13. @rishi:

    Well, if you don't need the kill switch, you can do everything like I did, just without it. Nothing special. Everything is going to work just fine without it.

    The latest design is here:

    Read the comments above, we did talk about immobilizes...

    I can't really give you a step-by-step instructions, or a diagram, since I didn't do this on a car with EWS.

  14. Just finished doing this mod to my car E36 96 318is. It works really fine. Thanks for the instructions. My ignition cylinder wouldn't turn on or off so I had to stall the car. The parts from Germany were going to take three weeks and BMW wanted $800 for one key and the barrel without labour!!! How much they would have charged me is anyone's guess but they are very expensive here in Australia. So I'm thinking in the vicinity of $1100 all up. However the parts I bought were only $120 plus a half days cutting and soldering wires.

    It's very easy once you have identified the wires and the connector. The start button that I bought was easily placed in the sunglasses recess. It hides in the shadows and is out of the way.

    Thanks for all of the input and diagrams! you saved me the better part of $1000.

    Best wishes


  15. Hi Bruce!
    It's great to hear that this article helped you.
    It gives me motivation to continue working on the blog.

    Marin M

  16. As a side note I only cut the wires that were detailed in your article. As a result of not cutting all of the wires to the connector I am still able to use the central locking and I still have power for the internal lights which is great for entering your car at night. Everything else is fine.


  17. thanks mate tried what you wrote on my bmw 316 1996 worked like a dream, the only mistake i made is I should have made a youtube vid to.

  18. Hi there, I've wired it up properly ACC switch works, ignition switch works but I can push to start? Can anyone help me out please?!?!

  19. @JR1 - Take a look here, and see if your wires go like on my conclusion scheme:

    If not, let us know a bit more details...

  20. Thx for the article, it helped me to rewire the ignition of my 318is coupe. Anyway, i`ve wired the switches in a different way, since i wanted to replicate the EXACT functioning of the key.

    Here is how i decided to wire it: http://imageshack.us/photo/my-images/4/86603572.png/

    Now when the first on/off switch (can be called "main switch") is off, the other switches are both disconected.
    To be able to start the engine, both switches must be on.

  21. can i use cig lighter as starter button? how would i wire it.

    1. No, I think you still need an actuall button, and then you can put it in the spot where the cigarette lighter is.

  22. so is he saying the red and violet are connected to one switch while the green and black are connected to the other while the start button is only connected to the black/yellow, duh? Or is it still red-violet, red-green and red black. i dont see the difference in the two diagrams.

    1. Here's a better diagram:

      Open and save it, and take a look :)

  23. Well I have a 2005 bmw325i. Can someone please help me with a diagram to start the car without the key like putting a push button. All help greatly appreciated. Thanks in advance