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Old 09-28-2012, 01:18 AM   #30
Registered User
Join Date: Aug 2012
Location: Tucson
Posts: 138
My Ride: 2000 323i
Neutral Safety switch (NSS)

Ok guys, so I finished up the nss. I'm going to show you guys how I wired it up, and also how I mounted it. Now, you can come up with your own configuration, as long as it doesn't allow the vehicle to start when it is in gear(this applies to manual transmissions). Now I've done this type of setup before. This is probably my 8th time making a nss in a stick shift. The first time I made one was in a mazda 6 back in 03. It as very elaborate, with an actuator and a switch, and it engaged every time you pushed the e-brake button. What I learned as I went through all the other fabrications of the nss was that the less complex it is, and the fewer moving parts it has, the less likely it is to break down. This is one of those examples where KISS (keep it simple stupid) truley comes into play. So this is what I recommend doing, but you can make your own version.
The materials you will need are as follows: 1. Magnetic switch (dei part number 8600) 2. spdt relay. 3. back strap bracket ( the kind that comes in the box of actuators and aftermarket radios). 4. 16 -18 awg wire. 5. 2 inch by 1 1/8 inch u bolt (got mine at Ace for $.99)

Here is the basic diagram of how this nss will be wired up.

We will be using our e-brake to supply our ground signal. That way we have a redundant safety system. Not only will the vehicle not start if it is in any gear, but it won't start if the e-brake is not engaged. Disassemble and lift up the center console to access the e-brake wire.

Now tap into the e-brake wire.

I tapped into 12v swithced at the radio harness. It is violet/white. Then I hooked up my relay and installed it right here.

Here is what we want to end up with.[IMG][/IMG]
Basically what happens is this: When the shifter is in neutral, the connection in the mag switch is broken, so the relay remains off. Since we have our e-brake hooked up to the n.c (normally closed) contact of the relay, we have continuity between the e-brake wire (pin #87a) and the nss input of the alarm (pin #30) when the relay is off. So the alarm gets the ground signal from the e-brake and we have a successful remote start cycle. When the shifter is in any other position, the connection inside the mag switch is made, and the relay turns on. Once the relay turns on, the connection between pin 87a and 30 is broken, and we no longer have a ground signal to the alarm nss input, so we get a no crank remote start cycle.

This is how I mounted it. I started by bending the back strap into a horse shoe like shape. That way I could mount my mag switch to the base where the shifter is. I had to take measurements all around the shifter, center console, window switch board, etc. that way I knew what kind of clearance I had and try to make sure my nss would not interfere with anything and have uninterrupted travel.

Next I took my u bolt, back strap and the magnet side of the mag switch, and mounted that around the shifter. I put the shifter in neutral and measured the distance between the center of the shifter and the center of the mag switch. I then cut a piece of back strap matching that distance. I mounted the magnet on the tip of the back strap. I first cut the magnet in half. The reason I did that was to reduce the size of the magnetic field, and give the switch a tighter tolerance.
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