Battery kill switch: POS+ or NEG-

[TrashPanda]

I plan to install a battery cut-off switch, mainly for extra security.
Oakland is currently rife with car theft, and I'd like a little more deterrent than my pedal lock provides.

I already have a marine grade switch like this one:
https://www.amazon.com/BATTERY-CUTOFF-SWITCH-BOAT-RACECAR/dp/B003BQLZ36

But I may spring for this one, for even more security:
https://www.summitracing.com/parts/sum-g1442

Both are rated 1000amp burst, 200amp continuous.

Just for ease of install, I intended to use the ground (negative) side. But it occurs to me that any patient, enterprising thief with cables and maybe a drill handy could just cut, crimp and fasten a new ground cable to the body, bypassing my security.
The thief would only have to know the battery location on the Vanagon. Given the number of stolen Vanagons in the area lately, I presume the secret is out.

So my plan is to use the positive side, interrupting the cable below the van, just before it passes through the grommet and into the battery compartment. Of course, I will cover the terminals to protect against the elements, as well as add a fused jumper to keep the dashboard clock running. I'll also be sure my connections are secure enough to keep the cable from grounding.

What do you all think? Am I an idiot?
Do I go ahead with my positive plans, or will an outpouring of negative nancys talk me out of it?

[DuncanS]

I think you are over thinking it. Do a hidden switch which triggers a latching relay for the fuel pump and hand it in. Make sure you read the entire 7 pages of the topic as there are some quirky things that could happen depending on the wiring your car has. https://www.thesamba.com/vw/forum/viewtopic.php?t=706950 . Or a hidden switch grounding the green tach wire feed. It's right at the dash and easy to get to.

Duncan

[dobryan]

Do not mess with the positive cable unless you are sure you will never have an issue. The penalty for making a mistake is shorting it out in the future if something goes wrong and then you likely will be trying to put out a fire.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

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MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
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[fxr]

And don't use the first one - we have one of those (in the neg feed, natch) and it can go intermittent. We've wondered once or twice why the van wouldn't start, and this was the culprit each time.
_________________
Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300

[tjet]

The Neg side is where BMW installs the disconnect switches when they ship new cars from Germany.

[TrashPanda]

Once upon a time, I used the rear defrost switch in my old '75 BMW 2002 as a starter cut-off switch. Not sure whether anybody tried, but it was never stolen.

I made that choice at the time, instead of a fuel pump cut-off, because I didn't like the idea of the battery being run down / the starter getting overheated and worn out. I may do something similar, here.

But, if early responses are any indication, I should stick to the ground side for any full-on battery cut-off.

And I should continue to ignore my reckless instincts.

[the joker]

Bet you wish you had that BMW 2002 , I also had one 1972 2002 silver/blue


use the summitt switch, neg side it's easy to install ,hidden make it accessible while in the drivers side be, creative.

There made for racing, shutting down the electrical systems fast.

Find the model with plastic red key, also handy to shut down for long term storage, or electrical work

[cmayna]

TrashPanda,
Do you have a manual or automatic transmission?
_________________
'90 Westy / automatic.
If I'm not working on the camper or my '50 Chebbie truck, I'm either fishing with the wife or smoking Salmon.


Craig

[Vanagon Nut]

A proper easy access switch on starter battery negative post might also help slow down damage due to an electrical short.

@ OP: did your BMW starter disable set up use a relay on 50 circuit to starter solenoid?

Thinking like a thief, if I couldn't even get the starter to turn, I'd bail. However, if I lived in a higher crime area, I'd likely install a fuel relay cut off and starter disable.

Neil.
_________________
1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[Zeitgeist 13]

I owned a '76 2002

Just like my general outlook on life, I'd opt for negative.

[16CVs]

We've been installing proper "HELLA" switches on the negative side. If you mount the cutoff switch at the front of the seat base you can just use 2 off the shelf straps and the install is straight forward, and when installed it that position it is easy to get to when needed in an emergency.

Stacy
_________________
1987 Syncro Westfalia Triple knob (bastard)
1989 Syncro Tristar Triple knob "Swedish"
2013 Jetta Hybrid a true "Zwitter"
Samba member # 14980
Call anytime number 650 722 4914 .
Keep Your van running and upkept tastefully for the love of the hobby.
Don't let your van end up in an "abortions" thread.

[Butcher]

Don't forget to put in an AirTag and bring a gun when you retrieve it.

I would probably not get a battery disconnect since I hate resetting all the clocks, radio stations, etc. Maybe rethink this. Something that does not allow the engine to start. You know, where the engine cranks, but will not start.

With all the cat converter thefts around here, they are already carrying the tool that can disable any pedal lock. Battery switches are difficult to hide so not much deterrent. I'm pretty lazy so it would have to be something simple to engage/disengage.

[fxr]

[dobryan]

[DuncanS]

I have an unfused negative from the cut off switch which feeds the radio, in/out temp gauge and my windows only. They are separate grounds and do not connect to the body tin. Clock is AA battery quartz analog.

Duncan

[TrashPanda]

Thanks to all of you for your thoughtful responses.
I'll stick with the negative side, and I'll spring for the Summit lockout switch.

To assuage my concerns over a thief just running their own ground strap, I'm thinking now I'll just try to keep them out of the battery compartment with something like a hasp lock.

I appreciate the linked thread. I particularly like the idea of using a 3.5mm headphone jack (and relay) as a starter cut off, with a matching plug wired POS to NEG. I forget who suggested that. Genious. I built some Grado style headphones a while back, and still have spare jacks and plugs around. So I might do that one too.

As for the off-topic: my van is a manual; I sometimes miss my '75 2002 and the '72 I had before that one. But I wouldn't trade my Vanagon for either. They were a hell of a lot of fun for a few hours of twisty roads. But my Vanagon can offer straight days, or weeks, of fun.

Thanks, again, to all of you for sharing your wisdom and keeping me out of trouble. This forum is an invaluable resource.

[Butcher]

[DuncanS]

A separate ground to the radio and you don't have to reset the presets. Clock ground can be isolated as well. No fuse needed.

[fxr]

[Ahwahnee]