e36 Electrical Kill Switch Install

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modifiede30
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e36 Electrical Kill Switch Install

Post by modifiede30 » Sun Jul 28, 2013 9:17 am

Need a little help. Wiring in my kill switch and from all the diagrams I've seen, I'm unsure about my plans.

My plan was to route the main power feed from the batter to the large terminal, the alternator feed to pin 1, then a single line to the batter from the other large terminal. This will deal with the main power sources and the alternator.

From the other side of terminal 1 I'll run a wire to the resistor and to ground to purge current from the system if I shut things down. I've heard this is unnecessary on BMWs but I don't see any harm in doing this just in case.

For terminal 2, I'll tap into the ignition wire line and attach it to each end of the kills switch terminals to break the connection.

Anyone have suggestions on this approach - seems to cover what I've seen - the only concern I have is the ignition - is there a better option that won't create problems with the ecu - should I just kill the ecu instead?

Here's the wiring diagram I'm working from.
http://www.google.com/imgres?imgurl=htt ... CA&dur=484
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Re: e36 Electrical Kill Switch Install

Post by 962porsche » Sun Jul 28, 2013 10:13 am

are you just looking to cut the power from the battery and keep the ignition key and switch ?
or are you looking to install a fuel pump on stitch with a ignition on switch plus a push buttom start ?

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Re: e36 Electrical Kill Switch Install

Post by modifiede30 » Sun Jul 28, 2013 11:50 am

I'll be keeping the ignition/key from the stock configuration - so cutting power from the battery and anything left from the alternator.
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Re: e36 Electrical Kill Switch Install

Post by 962porsche » Sun Jul 28, 2013 7:45 pm

where are you mounting the cut off switch on the car ? to the top side of the right QTR panel ?

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Re: e36 Electrical Kill Switch Install

Post by modifiede30 » Sun Jul 28, 2013 8:56 pm

I want to run 2 - one I can reach and one on the exterior - was thinking of mounting the exterior one on my roll bar since its a convertible.
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Re: e36 Electrical Kill Switch Install

Post by 962porsche » Sun Jul 28, 2013 10:26 pm

if it was me i would not opt for installing two cut off switches .
i would find a way to mount one that you can get to strapped in with your belts on that would have a cable to the out side of the car with a pull ring on it to turn the switch off .

is your car OBD1 ? if so you will have a much easier job for the install as you can just use the large battery posts on the cut off switch .
you when can just cut and pull back the +pos battery cable leads crimp and solder all the wires back together with a new end to match the cut off switch . then run a new pos cable from the battery and install a in line mega fuse . you can buy large mega fuse and holders at DEL CITY . com install the in line fuse as close to the battery as you can this is in case you crash the car and the power feed grounds it will pop the fuse . del city will have all the parts you need to do the install and they ship things quick . in theory you just moving the battery post to the back of the cut off switch . so you will want the wires that are now at the battery pos to be moved to the cut off switch and then just a single battery cable to the in side of the switch .

if the cars ECU needs to have power to hold it's memory there is a hole other way you will have to install the cut off .

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Re: e36 Electrical Kill Switch Install

Post by modifiede30 » Sun Jul 28, 2013 10:57 pm

Its OBD2 - thought about the pull-cable and I'm still muling it over. I have already fabricated a panel for the fire pull cable and kill switch that's in the center console - had planned to have a redundant pull cable for fire to the exterior, but that can be done by routing the cable to the tank location rather than the key/switch. The electrical one is more challenging to route and make it work.
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Re: e36 Electrical Kill Switch Install

Post by 962porsche » Mon Jul 29, 2013 10:41 am

ok so i was just looking at the schematic for the late E36's there does not seam to be any learn as you drive in the BMW's OBD 2 system so you should be good to go with hooking up the cut off the same way as it is for the OBD 1 .
with some ECU's you would have to have a powered ECU all the time even if you install a cut off or the ECU has to learn every thing all over every time you shut off the kill switch .

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