Best place for a battery cut off switch

[hdavis]

I want to install a battery cut off switch, and wonder where the best place is?

I want to be able to operate it while siting in the drivers seat

Thanks

[skinnerd]

I've seen them sprout out of the center mount speaker grill on the top of the dash....ala RSR.
Or some have been placed in a clock plug.

I put mine under the dash in the middle just to the right of my gas pedal.

All 3 locations can be easily reached from the driver's seat.

[304065]

The best place to locate the switch is immediately adjacent to the battery and operate it with a pull cable from the cockpit and one from outside of the car.

The factory put them in the grille, or down on the floor. There are two problems with that approach:

1) The battery cable is not normally routed up behind the gauges, which means extra cable length, adding weight and increasing the risk that the positive cable shorts against something up there (windshield wipers, other wires)

2) To be effective as a cutoff switch, the switch should be ideally located as close to the battery positive terminal as possible. The whole reason to install such a switch is to be able to isolate the battery cable from the body sheetmetal in a collision that compromises the cabin. If the switch is located at the end of a ten foot cable up inside the dash, that's ten feet of live cable that can start a fire.

The one in my race car is actually in the dash where the radio used to be but that is a very special case insofar as there is a lightweight battery in the smugglers box a short distance away and there is massive shielding in between.

A reminder about the switches: if you intend to actually use the switch to stop the engine you MUST get the six-pole FIA type switch. If you disconnect the battery while the engine is running you will destroy the alternator.

Now invariably some bolshevik will offer "I use the circle-track style two pole and my alternator is fine!" To which I say, "If you want to destroy the alternator it would be better to take it out of the car and beat it with a sledgehammer in front of your neighbors." Our wheezy electrical systems are one step above Citroens, they aren't your grandfather's AC Delco unit that could power the City of Los Angeles!

[hdavis]

Thanks for the suggestions, it indeed makes sense to have it as close to the battery as possible, but it is not very practical. I wonder how well the pull cables work though...

Anyone had any experience with the pull cable approach?

[jameshtaylor]

Pull cables work perfectly. Mount the switch near the top of the shock. Orient it so a short piece of wire/cable will open the switch when pulled from the corner of the hood. Run the wire out at the corner and add a handle of some kind. You can see the wire in the second pic. Make the wire long enough so you can grab it from inside the car. When not at the track, tuck the wire inside.

[hdavis]

Thanks, great pictures

[RSTarga]

I put mine under the dash to the left of the steering wheel.

[hdavis]

I put mine under the dash to the left of the steering wheel.

Except for the long live cable issue this seems to be the more practical solution...did you use the six pole FIA type?

[Todsimpson]

The best place to locate the switch is immediately adjacent to the battery and operate it with a pull cable from the cockpit and one from outside of the car.

Ditto on that...for the same reasons as stated. It's much easier and safer to route a pull cable though the trunk than lengths of positive battery line.

Check out this site...http://www.buckley-racing.com/products.html

I fabbed my own bracket, and used this switch and pull cable. If I had to do it over again I would buy the bracket as well. In my car the switch lives right next to the battery and the pull cable goes to the hole in the cowl where the windshield washer used to be. The pull cable is plenty long and could be routed to lots of locations in the interior.

[Bobs 67S]

When folks talk about the "cable" most are referring to a shielded cable like a bicycle brake cable. The outer sleeve can be routed and fastened in place.
The internal wire (aircraft cable) can have one of two pull ends:
1) a bull knob, usually a T handle
or
2) a 3" (or so) loop at the pull end with a short section of 1/6" hose covering the loop and the wire fastened to itself with the aluminum ferrule sleeve. This can be folded inside the hood when driving on the street and extended out of the trunk lid seam for track use.