Battery Disconnect (Cutoff) Switch)

[CDL1542]

Hey everyone, I decided that popping the hood all the time to disconnect the battery was getting a bit old and I wanted to install a battery disconnect switch (one with the red removable key) and actually had one from a while ago. My question here is on how big the wire gauge needs to be (and still be safe), and how I should go about making or where I can but the wiring components necessary. I have a spot for it on the dash and thought I'd ask for some tips especially from the guys that have done this kind of thing before.

 

Chris

 

Edited April 17, 2016 by CDL1542
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[beermanpete]

The switch and wires must carry the starter current so 4 gauge is the minimum size. We have 1/0 in ours.

[cbuczesk]

Why do you want a switch and why do you want a removable key? I bought wire, wire ends and shrink tubing from Summit Racing when I did my 240Z race car. I have a switch with a non-removable key mounted in the glove box area. Mine is set to cut off all the power to everything and cuts off power to the MSD so the car shuts off when the switch is turned off. I don't remember the gage of the wire but it's the same as the battery cables.

My Pantera came with a removable key switch and it's mounted in the "trunk" near the battery. The only negative I see with a removable key is that you could lose it...and I would/will.

Chuck

 

[beermanpete]

Most of the cars I have seen with a removable key on the battery cutoff switch have a tether of some sort that attaches the key to the car body to prevent losing the key.

[Jeff G 78]

I like the removable key since it's an easy way to ensure nobody accidentally tries to start the car or power it up.  With several teammates working around the car, weird things can happen.  It also serves as a crude anti-theft device since the car has no traditional key.

[CDL1542]

Thanks for the posts guys! Was starting to think I was out of luck with this. There's a few reasons I want a removable key:

1) Added security to prevent someone starting the car without the key to the battery in as well as a key to the ignition.

2) Car is still a work in progress and I always like to disconnect the battery when working on anything to prevent fire, zapping myself, blowing fuses, etc.

3) Regardless of how the car is, I always disconnect the battery when I'm not running it just in case... you never know when something might have a bad ground and spark. Adding a switch with a key lets me do this without popping the hood and removing the battery cable every time I run the car.

4) Prevent any potential battery drain when not running or if it's been sitting for a while (shouldn't be a problem, but I like to be safe)

5) I actually already have the switch with removable key that I got with some parts a while back and the idea has always appealed to me so I want to put it to use. If anything else, knowing that it takes an extra key to make the car run puts my mind at ease and won't have me worried that someone is going to steal it.

Losing the key doesn't worry me too much. I could always hide an extra one away somewhere discretely in the car. It would be the same as worrying about losing my normal keys. The wire gauge was my main concern and if I should go about cutting power straight to the negative end of the battery like I originally intended to or if I should go about it another way. I was thinking that I would have to use the same gauge as the battery cable but thought I would ask anyway. The last thing I need is to start a fire or melt any wires.

[John Coffey]

A kill switch with with an alternator ground is a good idea.  Keeps from burning a diode if your alternator is internally regulated.

[CDL1542]

Well I picked up some 1/8" thick ABS plastic with the same grainy pattern as the heater panel so we're off to a good start!