• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Theft Protection

Share this page

twas_brillig said:
I'm looking for a switch (or some form of relay) that would be normally 'off' but when switched to 'on' (and with voltage being provided to one side),it would stay 'on' until the voltage to the circuit was switched 'off'.
The concept would be to put the switch into the distributor circuit (per Nelson/Gerard). The switch is normally open. You turn on your key and energize one side and then (need two hands!) hold the switch/button/whatever down while turning the starter over. Turn the ignition off later, and the switch goes back to 'open'.
I'm both lazy and dumb, so looking for something fail safe, where I won't have to remember to turn my 'secret switch' off each time I turn the ignition off.
Any suggestions/ideas? I seem to recall seeing such a switch in instrumentation, years ago.
Thanks
Doug
Click to expand...

Hmm, if I am understanding correctly, you really just want a push switch that is hidden and needs to be pushed in order for the ignition key to work. Basically just cut your positive (assume normal gnd) and put the push button in between it...unless I missed something?
 
Sarastro said:
I think that you're describing what we electrogeeks call a "latch." Attached is one way to implement it. The idea is that you cut the white wire from the ignition switch to the fuse and insert this circuit.

You could also put this into the white wire from the fuse to the ignition coil, if you wanted it to affect just the ignition. Might confuse a thief even more that way.

When the ignition is turned on, nothing happens. Then, when you push the button, the relay coil is energized and closes the relay's switch. This applies power to the car's electrical components, but it also creates a path that keeps the relay coil powered when you release the pushbutton, so everything stays powered. When you turn off the ignition, the relay coil is no longer energized (nor is anything else) so it all goes off.

The button should be fairly husky--I'd make sure it is rated at at least 5 amps DC. It carries the full current of the switched circuits for a fraction of a second until the relay closes. You could get around this problem by putting a large diode (like a 1N4004) in place of the wire from pin 87 to 85 of the relay, but that's starting to get complicated.

Of course, I haven't tried this, but it should work. I might have overlooked something, but if I have, and it doesn't work, you're out only $5 for a relay, a button, and some wire.
Click to expand...

This was my original thought. But if the car has an electronic starting solenoid (not the pull switch) you can just put the button in between the ignition wire to the solenoid. Simply, effective, and any cheap 12V switch should work...no need for relays.
 
I have that exact circuit on my fuel pump- it allows someone to drive about 1/2 mile (max) and then it runs out of fuel. I think that it will frustrate a thief more than if he can't start it initially.
BillM
 
The trouble with the switches described above is that you have to switch them to 'off' when you park, and my memory ain't that disciplined or reliable.
I really want something that will switch itself off, which is where the idea of a switch/relay/latch comes from: turn the ignition key off, and the ideal device would reset itself to the 'off' position.
Doug
 
twas_brillig said:
The trouble with the switches described above is that you have to switch them to 'off' when you park, and my memory ain't that disciplined or reliable.
I really want something that will switch itself off, which is where the idea of a switch/relay/latch comes from: turn the ignition key off, and the ideal device would reset itself to the 'off' position.
Doug
Click to expand...

What I described is a push button. It is on a spring so you push it and it turns on, you turn the key to start the car, then release the button.
 
Ah Ha! The light comes on! t'would work with the dune buggy, where I've got two buttons as described: one for the horn, and the other for the windshield washer.
Steve's thoughts will hopefully work for the bug-eye, and maybe it or the push button on the 3000, wired in (per an earlier suggestion) to the fuel pump or to the coil.
I think we've got some good ideas here!
Thanks
Doug
 
I purchased a Standard SSB-2 Starter Button Switch for $ 9.74 last night (I think you guys south of the line have the Big Dollar these days) and we're going to install it in the dune buggy. We have a standard VW steering lock/ignition switch; I'll install this switch in the angle iron providing the driver's side front seat support. Turn on the ignition key and try to start it and nothing. Instead, on with the key then reach between your legs (in a manner of speaking) and under the seat and hit the starter button. Kind of like a weird British starter.

If I had a headlight dimmer switch as part of the steering column, then I'd install a Standard DS70 'Switch/commutateur Interrupteur' (an old fashioned foot dimmer switch) and wire it in somehow for the starting circuit or the distributor. The whole idea here is to confuse any poor bugger trying to hotwire/otherwise steal the car.

For the bug-eye, I picked up an Atlas RW1200 'Realy & Connector kit 5 wires' and will look at installing it and a push button somewhere and connecting it in the distributor circuit per the earlier sketch (I'd say thanks to the author, but can't page back to find it). Cost was $ 13.95. And 'Realy' is the way the label spells it.

Later
Doug
 
Get a line lock like drag racers use to lock the front brakes for burnouts. Lock ther brakes when you park and it won't matter if they can start the car or not. They won't be able to push it on a trailer either. They may get wise and next time bring six guys to pick it up.
 
:iagree: Ignition locks are virtually useless because these cars are so easily hot wired.
 
For about $100 you can make a GPS+Pre-Pay cellphone circuit that you can text to ask where it is at and then it will text you it's GPS coordinates...only have to make sure to have minutes on the phone...I am planning something along these lines when my car is nice enough to steal...
 
please post and share when you work out the system.
Thanks
Doug
 
I have the original 1970 ignition switch still in place on the steering column, and the working switch is in the 67 dash. When I park the car I would crank the wheels hard over, and pull that lower key. Anyone looking to push or pull that car would end up making Spirograph patterns in the parking lot.
 
Back
Top