Kill switch / quick question about wires and that

dhardyuk

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Morning all

I'm in the world of pain that is a 1500 page PDF of all of the possible combinations of wiring anyone could ever imagine might have been needed for troubleshooting T6 electrics.

I have gleaned so far that SC56 is the magic fuse that's needed to start the van.

If I follow the black wire from the ignition switch in the diagrams that links to terminal 56 on fuse SC56. There is then a black/blue wire that heads off from terminal 56A towards the engine bay. Logic tells me that I should be able to locate the black wire somewhere between the steering column and deep under the dash behind SC56. I'm obviously going to have to make a joint somewhere awkward to get to in the depths of the dash - this can be made easier by cutting the black wire somewhere accessible and splicing in a length of black wire so I have a loop of slack to do my shenanigans on and then tuck that away with a couple of cable ties somewhere to make it awkward to get to.

So questions, is that reasonable? or is there some crafty trick that everyone else does instead?

What I don't want to do is get in the way of the start-stop gubbins or break the immobiliser etc etc.

Of course, security and all, the information on how to chop in a kill switch is scarce in all of the places I've been looking so I'm doing empirical research. I am about to do some tests using a nifty 3d printed fake fuse that will allow me to check (the always check twice, before cutting, check) when that fuse is needed and when it can be safely disconnected without breaking anything.

3D printed fuse plug.jpg

My final plan is to embed the wiring into the loom, so the switch won't be defeated simply by pulling the fake fuse and popping a real one in. Unless that is what everyone else does.

Once I've got it all figured out I'll write it up and include links etc as needed.

This is an interesting approach to hiding a kill switch:
How to Make a DIY vehicle immobilizer to stop car thieves

The circuit was created in 2010 and has been lost from the Internet but has been crawled by Internet Archive: Digital Library of Free & Borrowable Books, Movies, Music & Wayback Machine:
Welcome to the G-Spot

Thanks for reading :cool:
 
You should be able to interrupt several circuits that will prevent the engine running, for instance the fuel pump the wiring of which might be easy to intercept in the seat base.

It all depends what kind of threat you are defending against. A modern professional thief knows a target vehicle electrics as well as anyone so you need whatever you do to not be found trivially, so you might want to choose something that seems to be a fault rather than obvious security. For instance if you want to block the OBD port than interrupting the power line works but is very obvious, but interrupting the data bus just looks like an electronic fault to someone in a hurry.

Are you going to set it every time? Are you going to have to explain it to other drivers? Anyone who services the vehicle with a legitimate reason to start the engine who you wouldn't want to know about your security? A full immobiliser will do those, a hidden switch broadly won't.
 
I'm focused now on assuming the biggest risk I have is a theft with keys. OBD port is already disabled.

It started out as "I want a Ghost immobiliser" and became "I want a cheaper than Ghost immobiliser" and finally "I want a kill switch".

The "I want a cheaper than Ghost immobiliser" options I found need an analogue cut and relay as apparently the power train can bus doesn't expose a way to stop the engine. So If I fit a kill switch for now, the option is there ready for a relay to be added in later when I have the pennies to upgrade from a £2 switch to a something better.

Once everything is identified its not hard to wire a second switch in parallel for an override or valet/servicing mode. That bit is the easy bit!!
 
Part of the challenge is where to mount such a switch so that it is not obvious, is easy to get to so you don't forget to set it yet isn't going to be knocked or mistaken for something else when driving, killing your ignition on the motorway is likely not going to end well.

I've wondered in the past about getting an option switch for an option I don't have, but there is always the risk of someone accidentally pressing it for it's "advertised" purpose or fumbling in the dark for the real button next to it.
 
Where do you find the fake fuses BTW, I'm considering something similar to intercept some wiring at a fuse for other reasons:

 
Where do you find the fake fuses BTW, I'm considering something similar to intercept some wiring at a fuse for other reasons:

I tinkered it on Tinkercad

3D design 12V Fuse plug shell | Tinkercad

and a bag of these https://www.amazon.co.uk/dp/B07MKYF2MP
 
I was hoping for some more comments here, about a cheap easily DIY kill switch. I'm only interested in a simple switch to add another layer of inconvenience rather than an almost foolproof method. (it's only a 2015 T5.1 cheap conversion, so not so attractive they will spend hours to steal)
 
I'll give you one. Find the fuse for the starter. Pull it out. Happy days.
OR
Switch? Get one of these......


61OV3EgmSjL._AC_SL1500_.jpg
....and one of these.....

61cyiS6LUUL._AC_SL1500_.jpg

.....and some of this.

61Kxn7sB2PL._SL1000_.jpg


Cut the fuse holder wire anywhere you like. Cut 2 lengths of the cable above and attach them (solder or just thread, twist and tape up) to the switch pins then attach the other ends to the wire you just cut on the fuse holder. Fix the switch somewhere in the van. Take starter fuse out and stick it in the fuse holder and stick the prongs of the fuse holder to where you took the starter fuse from.

Switch off, no starty, until switch on.

Jobs a good 'un.

If you get a rocker switch instead of a toggle switch then that's even better because not only do you have to press it while turning the key but when you let go the starter will be automatically disabled so you won't ever forget to disable the van. Downside to this method is stop/start wont work if you have that feature. It'll stop. It wont start unless you're pressing the switch.

Never gonna stop a master criminal but the beauty of this method is it's also easy for you to bypass if needed, like when taking it to a mechanic.
 
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I'll give you one. Find the fuse for the starter. Pull it out. Happy days.
OR
Switch? Get one of these......


View attachment 232316
....and one of these.....

View attachment 232317

.....and some of this.

View attachment 232318


Cut the fuse holder wire anywhere you like. Cut 2 lengths of the cable above and attach them (solder or just thread, twist and tape up) to the switch pins then attach the other ends to the wire you just cut on the fuse holder. Fix the switch somewhere in the van. Take starter fuse out and stick it in the fuse holder and stick the prongs of the fuse holder to where you took the starter fuse from.

Switch off, no starty, until switch on.

Jobs a good 'un.

If you get a rocker switch instead of a toggle switch then that's even better because not only do you have to press it while turning the key but when you let go the starter will be automatically disabled so you won't ever forget to disable the van. Downside to this method is stop/start wont work if you have that feature. It'll stop. It wont start unless you're pressing the switch.

Never gonna stop a master criminal but the beauty of this method is it's also easy for you to bypass if needed, like when taking it to a mechanic.
Thanks for that idea. What do you call the top fuse bypass thing, so I know what to search for on ebay?
 
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