Battery cut off/isolator

[itsallyellow]

I have been told different things by different people!! Some people say i need one on the inside and one on the exterior. But msa say just one on the outside??

What do i actually need??

thanks
mike

[chassis 33]

You need one that you can get to and one that the marshalls can get to, despite what the blue book technically says, you don't want to be waiting for a marshal to be scurrying along if you're trapped in a car after a shunt, the powerleads have shorted and are causing an electrical fire. (WCS i know but that's what all of this safety lark is about)

Talking now about traditional, not solid state electronic versions) how this works is entirely up to you, some people (like I had last season) use two kill switches and trail wires all round the car wiring the switches in series (the down side is two bits of electrics to go wrong, and as we all know electrics are the spawn of satan and should be kept to a minimum wherever possible.
Another way is to have one controlling everything, say on your dash, and a pull cord from the outside to the isolator.
I have seen a setup where the isolator is right next to the battery and uses pull cords from both dash and exterior.

The location of the marshalls control is defined in the blue book, either on the scuttle or in the "B post" area, IIRC

Regards
Iain

Edited by chassis 33 on Monday 12th March 11:19

[itsallyellow]

Thanks!

[teamHOLDENracing]

The traditional method is to have the isolator 'key' switch mounted within reach of the driver with a pull cable (like a fire extinguisher pull) tethered to it and mounted on the front scuttle. You rig it up so that a tug on the pull cable rotates the key inside and cuts the power off. You should keep the power cables as short as possible. The alternative that Iain hints at is the electronic cut off, which has a button on both the inside and outside.

I was having a root around my spares this morning and I have two new isolator switches with keys if you are interested. I have the normal and FIA versions (the latter has additional terminals to route a dump to earth (via a resistor) off the alternator) - you can have them at 20% less than the Demon Tweeks price. I may also have a pull cable.

Beware the last point - you often see cars where the engine doesn't cut off when you hit the kill switch - the output from the alternator continues to power the car despite the battery being cut off. And the scrutes do check this.

Cheers

Andy

[itsallyellow]

So how would you connect a pull cable to an isolator?? I cant think how you would make it turn??

thanks
mike

[chassis 33]

Very quick sketch for you...kinda like this
As the cable is pulled, the linear motion of the cable creates a moment about the centreline of the switch, causing the switch to turn.
Regards
Iain

[itsallyellow]

Thanks. Kinda simple really!!