FF Battery Cutoff Switch Install Tips

[MaxVmo]

Looking for guidance on installing the FF provided cutoff switch. I’ve decided on the pedestal between the seats on the slant panel above the transmission cover.

As pictured, I’ve removed the red switch. There is a post on the side of the unit—do I need to drill a hole for this (and what is it)? What’s the recommended drill info? No instructions are included. Thank you all!

[Nigel Allen]

The post is to prevent the switch body rotating. Best practice is to switch the negative cable.
It looks like a Cole Hersee switch. Have a dig around on their website, hopefully you can find a drawing to create a drilling template. Then again, don't overthink it, just get some vernier calipers and do the calculations.

2 of the handiest items for building these cars:
- step drill for aluminium panels.
- digital vernier calipers.


Cheers,

Nige

[CraigS]

As Nigel says calipers are a great tool and fortunately no longer that expensive. I have a metric and a fractional caliper from back in the 70s and they are still going but most often I grab this;
https://www.homedepot.com/p/Husky-6-in-3-Mode-Digital-Fractional-Caliper-1467H/206007130

[gbranham]

As Nigel says calipers are a great tool and fortunately no longer that expensive. I have a metric and a fractional caliper from back in the 70s and they are still going but most often I grab this;
https://www.homedepot.com/p/Husky-6-in-3-Mode-Digital-Fractional-Caliper-1467H/206007130

Agreed. I used my digital caliper just this morning. Super handy.

[Smiley]

Best practice is to switch the negative cable.

That is interesting, mind if I ask why?

The reason I ask, as an electrician, in the days of knob and tube, the neutral (grounded conductor) was switched, so while the device, say a light fixture or outlet was technically “off”, it was still energized, and people were electrocuted by wires they thought were “off”.

It seems the same is true here, even though the disconnect is off, everything will still be energized so a misplaced tool touching any terminal and the grounded frame would elicit sparks and damage.

What am I missing?

Thanks, Steve

[BEAR-AvHistory]

https://thefactoryfiveforum.com/attachment.php?attachmentid=201059&d=1719510428

Have mine where you want to install yours. Two things different. On 'off' the positive circuit is cut not the ground. I have a low amp fused keep alive jumper across the positive terminals to allow current to flow to my computers, ECU, sound, etc. The fuse will blow under starter load killing the power.

[Mike.Bray]

I mounted my disconnect under the hood, the theory being it's another level of theft deterrent. I can turn it off, take the key, and close & lock the hood. Now if I can just find the keys to the hood latches....

https://www.imagecoast.com/images/MichaelBray1/20240411161124mediumrotated.jpg