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electrical cutoff switch

 
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Steve D



Joined: 09 Aug 2004
Posts: 102
Location: San Diego

PostPosted: Sun Jan 02, 2005 6:56 pm    Post subject: electrical cutoff switch Reply with quote

Hey racers out there - could someone give me some info on installing a master electric kill switch? (Where do most folks put them, how are they wired up, where do they come from, etc...). Thanks much!

...getting there!!
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Tom Olsson
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Joined: 03 Nov 2004
Posts: 242
Location: Seattle, WA, US

PostPosted: Sun Jan 02, 2005 7:53 pm    Post subject: electrical cutoff switch Reply with quote

Take a look at this site: http://www.ogracing.com/eshop/home.asp?categ=266

We're using the Longacre, as it's made of metal as opposed to plastic. We mounted it on the passenger side valance, just in front (or is it behind??) of the firewall, next to the A pillar. On an E30, this is pretty convenient, as there's plenty of sheet metal there, and the power block is just below it. I'll dig around and see if I've got pictures.

That said, if I did it again, I'd take the time and effort to put it on the driver's side of the car. The corner workers will always approach the driver's side window to make sure you're OK, so it would make sense to have the kill switch and the fire handle on that side. I've also seen a couple of very nice installs with them both mounted just inside the window on the cage. Just have the cage builder mount a plate in a convenient place.

Oh yeah, one more thing. Make sure you've got plenty of clearance to the hood if you put it where I first described. A team mate got into a minor fender-bender, the hood came up, bumped the switch, and turned the car off.

[ 01-02-2005: Message edited by: Tom Olsson ]
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Tom Olsson
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Joined: 03 Nov 2004
Posts: 242
Location: Seattle, WA, US

PostPosted: Sun Jan 02, 2005 8:02 pm    Post subject: electrical cutoff switch Reply with quote

Jeez, I took a lot of pictures when we built this thing!

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Steve D



Joined: 09 Aug 2004
Posts: 102
Location: San Diego

PostPosted: Tue Jan 04, 2005 1:01 pm    Post subject: electrical cutoff switch Reply with quote

Thanks, Tom, for the guidance & the picture. I just ordered the same switch.

I noticed in the picture that it looks like you left the rubber insulation on the firewall. I've been debating whether it would be worth it to strip this off or not (heat & noise vs. weight). Any particular reason to leave this on in your opinion? This car-lightening stuff is new to me, so I'm kind of going by feel & looking for advice where available!
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Tom Olsson
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Joined: 03 Nov 2004
Posts: 242
Location: Seattle, WA, US

PostPosted: Tue Jan 04, 2005 2:15 pm    Post subject: electrical cutoff switch Reply with quote

I would definitely leave all of that on, for safety's sake. It's also very important that you use the rubber grommets on the firewall. Otherwise vibration throught the car will wear throught the insulation, the positive will contact the car body (ground), and you'll probably have a fire.
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Steve D



Joined: 09 Aug 2004
Posts: 102
Location: San Diego

PostPosted: Fri Mar 04, 2005 2:13 pm    Post subject: electrical cutoff switch Reply with quote

Tom - thanks again for the info. I'm finally getting around to hooking this thing up & was wondering if I could tap your brain one more time. Your picture shows 2 wires going into the switch - one large & one small. Does the large wire go into the "Battery Switch" post, and the smaller gauge wire go into the second input? or vice versa? or does it matter? And what gauge wire do you have on the output - I'm guessing 2? What's the point of having two wires run through this thing? I guess I'm not fully understanding the installation instructions, which show two methods of wiring (one where the alternator is fed through the distribution block and one where it is not). Is there a "Alternator / Battery Wiring for Dummies" book anywhere??
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Tom Olsson
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Joined: 03 Nov 2004
Posts: 242
Location: Seattle, WA, US

PostPosted: Fri Mar 04, 2005 3:08 pm    Post subject: electrical cutoff switch Reply with quote

It's easier than you think. All we did is put the cut-off in between the battery and the power block. Take a look at the way the car is connected before you start. Disconnect the wires from the power block, connect those to the cut-off switch. Then make new wires of the same gauge (honestly I can't remember) from the cut-off back to the powerblock.
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Steve D



Joined: 09 Aug 2004
Posts: 102
Location: San Diego

PostPosted: Wed Mar 09, 2005 9:17 am    Post subject: electrical cutoff switch Reply with quote

Tom - you wre right, I apparently was trying to make it much harder than need be. Once I finally (after ump-teen trips to the store) got the right sized connectors & wires, it went on pretty easy. I ended up mounting in roughly the same place yours is in the picture, was too lazy to route wires over to the other side.
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