Dave H.

this is for security. no battery, no drive away.


just go drive the car...

Garth S

For consideration - If a cut off switch is installed on the battery ground strap, why not wire in a parallel bypass loop to the switch of modest gauge wire with an ~ 5 -10 amp fuse in line.
This will leave all critical circuits energized (LH, radio memory, clock, etc), prevent shutdown spikes - and if anyone tries to steal the car ( or is dumb enough to turn the key on the starter ), the fuse will pop immediately.
This assures all the protection desired of the cutoff switch - and provides power to modest draw circuits for a car in good electrical health: obviously, this approach is useless if a ground fault leak is an issue ....

ibkevin

Battery cut off switch.

greg928GTS

This is what I was referring to in my post.

Alan

Paul,
I have no leaks - but this is for emergency use - and yes there is a strong case for it - many unfused always active cricuits in a 928... also I work on my car a lot and this is a very convenient way to disconnect the battery when I need to (including to quick charge the battery). I also use it when I am detailing the car since then the doors/hatch/hood can stay open as long as I want. I do not use it as a security measure - though I could.

Turning the power on & off to the ECU's happens every day - get used to it... The constant power to the memory is the least of your worries... IMO.

If your ECU is going to go bad its because of circuit breakdown over time... partly related to ambient conditions... on/off stressing is not a primarty concern. Over voltage is a much bigger concern - but more from high power chargers or bad regluation than from pure circuit inductance - especially if you have a honking big decoupling capacitor there too.

Greg - my car has no ECU re-adaptation issues. I believe if the power is off for more than a very brief period a re-adaptation is not performed - John Speake will no doubt know for sure how this works and the times involved. I always turrn mine off for more than 30 minutes at a time and it has never given me any issues on restart that would suggest its even trying to recal....

Alan

Pfunde

I've got a system in my boat ( yes I know it's a multiple battery setup , but ) where a small ( and again yes 60 amp is not small, but in a boat with 8 * 200 amp) batt gives power to clock, remote swithes for main battery's, webasto heater, alarm etc. Couldn't you make some kind of dual solution like Normy suggest . Can't be that difficult ( I hope). My shark loose power aswell, and I never found out why. Now I just keep my battery charger in the car. For now it work's fine but I would love to fix it, one way or another !

F4GIB

Does the bracket come with the switch or do you have to make one?

Leon Speed

Thread resurection: where does the bracket come from??

Arnoud

See this post for photo's and a PDF file of the bracket profile I made (idea fully copy-cat from Alan Moore): https://rennlist.com/forums/9983682-post13.html

Mike B

Alan / Arnoud...what make/model switch did you use?

pevi

Here is my version

Leon Speed

Ok so it looks like I have to make a custom bracket.

Alan

You hace to make a custom bracket unless you can get a VW/Audi type - even then I think it won't work too well with the stock ground strap.

My switch is a Hella - there are knock offs that almost certianly don't work as well - I believe the Hella is about $12 the knock-offs are about $5. Choose wisely - you need it for the car to run...

With the Hella types you can get a rubbery plastic end cap, you can also buy spare handles - I have several.

Mine is fully behind the tool panel and lives normally with the cut off screwdriver operation handle end and an end cover - very stealty - most folks would ignore it. When needing to use it repeatedly I put the regular handle in.

Look in Del City, Waytekwire etc for all the parts you may need.

BTW you do need to make a very clean, solid, large gauge, well protected connection. If you use aluminum make sure its well protected and no chance of heavy oxidation build up and loose connections.

It might be technically possible to create a thermite reaction if you loosly bolted an aluminum conductor to a rusty steel ground point and passed a huge current though it - and that would be very very bad. Stick to the brass plated stock ground point and keep everything tight clean and protected from oxidation (use a connector protector - like a spray battery terminal protector).

Alan

Mike B

Thanks Alan!

Pfc. Parts

Hi Alan -

What's the yellow connector for? Looks like a bridge to nowhere in the picture?

Thanks,
Scott.