In response to the recent questions regarding my Push-Start, I am including an updated DIY and further instruction on how to use this mod to start the car in the event the ignition cylinder fails or to make the car truly keyless. On pre-EWS cars (> mid 95) this will eliminate the need for the key altogether. On cars with EWS (<96+) you will still need to insert the key but do nothing with it. Make sure that you double lock the car when doing this to a pre EWS car, as then anyone could drive it away.
For the basic Push-Start you will need:
1 30-Amp relay
3-4 feet of 14 or 16 gauge wire
To eliminate key use altogether, in addition to the above you will need:
1 Toggle switch with a high amperage rating.
4 feet of 10 gauge wire
Also, if you want to add this feature but don't quite know how or don't have all the tools to install a switch, I will now be offering a kit for $30 shipped that includes the switch (of your choice) pre-mounted in an expansion tab, prewired relay, all wiring and wire connectors, and start decal. All wires will come with connectors already attached, so all you have to do is take off the under panel and plug them in. PM or email me for more info. For $45 I will include the extra materials for the Totally Keyless option.
For those of you with the resources to tackle this on your own here you go. Part One: Trim removal
In order to install the button, you will need to access your ignition harness. To do so, you must remove the lower dash piece and the metal guard behind it. The dash is held in place by 3 Phillips screws. There is a small speaker attached; simply disconnect the plugs to completely remove the panel.
The guard is held in place by three bolts, all 10mm.
You can also remove the heater vent if you wish, it just snaps in/out of place. Next, you will also need to remove the OBC and sunglasses holder. The OBC is best removed by sliding a credit card under it at an angle and pushing out from behind it. There is a small finger-sized hole under it to push from the back. Once enough has moved forward, pull it toward you. You can unplug it to remove it if you wish, but you'll have to reset it later. To remove the accessory outlet and sunglasses holder, simply pull forward on the unit; it snaps in and out. To mount your switch in one of the expansion tabs, press on one of the retaining tabs on the back and it will pop out. You can mount the switch however you want in it. Part Two: Wiring The Switch
There are going to be three wires you'll need to access: Ignition, Starter, and ground of your choosing. The main ignition wire is the large green wire coming out of the ignition switch. You will need to tap that wire, using a splice or removing the insulation and wrapping the new wire around it. I suggest the latter, as the former did not work for me. Repeat the same procedure for the starter wire, which will be black and yellow or black and green. BMW used different colors one certain cars throughout the production run.
You'll also need to run a wire from the area your switch will be in to the other wires. There will be a small gap you can feed the wire through and pull it around.
The switch you're installing acts as a ground. I suggest splicing into the accessory ground. In between your ground splice and your wire to the ignition is your switch. Attach one wire to one prong and vice versa. Easy enough.
At the end of the wires near the ignition, I suggest attaching a spade connector, however tape will work. Part Three: The Relay
In order to make it all work, just plug the spade connectors into the relay as shown below, or tape the connections. Depending on where you buy the relay, it will have four or five prongs. In the event it is a 5-prong, the middle prong is not used. The 4-prong works just the same.
At this point, the car will start when the button is depressed and the ignition is set to "Run". If you wish to retain use of the key start, end now. If you wish to make it a button-only start, cut the yellow/black wire before your splice. Part Four: Show Off
If all you are doing is the button, reassemble and show off.