Ya I'm not disputing what makes sense electrically, I'm just pointing out the OP needs to ensure he's going to comply with the rules he's running under. Here's the NZ regs:

"closed dedicated motorsport vehicles are required to have an outside
method of triggering the ignition switch/circuit breaker, positioned approximately
at the lower windscreen mounting area. Identification markings, (refer diagram
5.2.5) shall be present next to the external switching position.
"

Make sense? Nope. Required if you wanna race? Yup.

Here's the CAMS regulation pertaining to our discussion:

10. Each automobile of the 2nd and 3rd Category shall be equipped with a battery isolation (master) switch which
isolates the battery and stops the engine. It shall be capable of being operated by the driver in his normal
seated position. There must be a second switch, or a remote means of operating the main switch, from the
vicinity of the base of the A pillar on the driver’s side or, for an automobile with no A pillar, in a comparable
position. This external device shall be clearly marked by a symbol showing a red spark in a white-edged blue
triangle of minimum edge length 150mm.

As you can see, it would be tricky to have the switch mounted in the boot and still comply with the regs.

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Curly
'64 Cooper 'S' (Group Nb spec)
'67 Mini Marcos GT www.mm7056.wordpress.com

I still can't see also why it has to be positive or negative cut off!

If we assume the battery cables make a loop then it doesn't matter where it's cut?

But I do agree a couple of things:

1. Cut off as close to battery as possible - preferably at terminal.
2. Cut of pull as close to driver as possible - preferably at A pillar (inside AND out) or similar.
3. Battery cut off also has to kill engine.

All good....

SMAC - where did you get the hardware?

_________________
Regards,

Mike
"He who dies with the most toys wins."

I see the logic of the negative instead of positive cut-out.

The whole car body is connected to the negative of the battery, so if you run a cut-out switch on the positive, ANY failure of the wiring or switch which makes contact with the car body will still cause a short (& subsequent nastiness).

If you put the cut-out on the negative side, then any shorts to body do nothing, unless worst-case you've isolated the battery and it still makes a circuit due to a short somewhere - hence running it as close to the battery as possible, less chance of a destructive short.

If we still ran positive earth cars then this would be all arse-about

cheers,

Jacob

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'72 Clubman Van - 1022cc, 295 head, 731 cam - Daily Driver
'69 Morris 1100 S - Dinged by a bus, in shed under repair
'64 Morris 1100 - Early 1100, long term project

Imagine a circuit that is connected to two terminals.

Disconnect the +ve terminal - system dead.

Disconnect the -ve terminal - system dead.

Disconnect the system anywhere in the circuit and reconnect the terminals - system live.

The key is to disconnect at or as near to the terminal. If I recall there is a short black cable and a long black cable coming from the terminal. If you disconnect as close to them as possible - sorted.

Do we drug test on Ausmini Forum?

_________________
Regards,

Mike
"He who dies with the most toys wins."

Is there anything to say you can't use relays/solenoids/contactors to do the isolation (as close to the battery as possible) and run control wires to switches anywhere in the car you want access???

Not for racing, as relays etc are prone to sticking.
Also the cost of a relay/contactor that can handle the starter current would be pricey. The mini starter solenoid only has to engage for a few seconds & would not be suitable for continuous duty.

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Too many cars, and too little time.

There are a few designs now coming on the market that are electric/solenoid based.

Beanie earlier on gave a link to one and I've seen others. They are actually being advertised as a much safer alternative because they are quicker to disconnect than a cable pull AND, if the power is disrupted, they cut themselves off anyway.

All a solenoid is is an electromagnet that throws a pole in one direction, which acts as a power switch.

Re the starter soleniod...as long as you keep the power on it will connect.

_________________
Regards,

Mike
"He who dies with the most toys wins."

I always put car audio amp fuses as close to the battery as possible. No point having a fuse on the other side of a short

Why not put two switches in. One that is accessible within the cabin on the positive, and another on the earth?

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No idea sorry, was on the car when I got it (ex Mini7, I put it back on the road).

Has anyone had experience with run on after cutting out the positive battery feed?
I have read that running a cable back to the battery side of the cutoff from the alternator will solve this problem?

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Tim

It is like fitting a fuse in a circuit, you put it the closest to the power source. If you switch the negative side it is always safer as there are no additional live wires going from the battery to the switch. Remember when you switch the positive you end up with the cable from the battery positive to the actual battery switch still LIVE even when the switch is turned off. That is a Hazard in itself. Cut the negative and nothing works, all safe.

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DID I MENTION THAT I AM THE BEST SUPPLIER FOR MINI ELECTRICAL PARTS AND REPAIRS?
"Let us remove your "SHORTS"

Not sure I'm following your reasoning there...if you switch the positive, you have a wire going from the battery positive to the switch...if you switch the negative, you still have a wire going from the battery positive to the solenoid and fuse box etc. Still not good in an accident situation.

I'm all on top of the negative vs positive thinking.
The way I have my car wired is a cutoff switch in the positive feed in the cabin.
This is primarily for theft purposes with a removable key.
I want to make it usable in emerg purposes (in the case of the positive not being shorted behind me)
I had read that run on will occur and want to rectify this. To me the suggestion to run an alternator positive feed back to the battery terminal of the cutoff will give it a constant 12v regardless. Don't I want to be removing alternator feeds altogether in a running situation?

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Tim

Im just going to wire it like this

http://www.batterydirect.co.nz/Bi596.JPG

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Tim