Anyone wired a self latching or other type of anti-theft kill switch ?

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273

273

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Gonna do a rewire job with trunk mounted battery to my car this winter and been looking for wiring anti-theft ideas, a self latching relay with hidden button trigger kill switch seems like a good option anyone install one ? How did it work out or is there better options/ideas.

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Back in the dinosaur days when i owned a 71 Hemi GTX, and a 71 Cuda, those cars still came with a cigarette lighter.
I never smoked, so i never needed to use those lighters.
I wanted to install a hidden kill switch, as a theft deterrent.
I remove the "guts" from the back side lighter, and installed a round, cylindrical, type of button switch in the housing.
Then all that i had to do was use the push on, push off, knob, to activate the switch, to kill the coil.
Always worked well, and it was a hidden kill switch, that you wouldn't know anything about.
 
I wired a hidden switch for power out of my key on my 71 Demon. I used a nice 40amp switch to make sure it would handle the power. It's under the dash but I'm sure if you got your head under there you could see it.

And the thing is I usually forget to switch it off though when I park the car!
 
Keith Mopar said:
And the thing is I usually forget to switch it off though when I park the car!
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That's why i think a self latching relay is the way to go, you'd turn the key to the ACC position then push the button one like hemi71x described would be kool which would arm/latch the relay then turn the key to start, but everytime you turn the car off it unarms/unlatches and needs to be armed everytime the key is turn to the off position. Stopping the need to turn off the kill switch everytime which I'd would usually forget to do.

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hemi71x said:
Back in the dinosaur days when i owned a 71 Hemi GTX, and a 71 Cuda, those cars still came with a cigarette lighter.
I never smoked, so i never needed to use those lighters.
I wanted to install a hidden kill switch, as a theft deterrent.
I remove the "guts" from the back side lighter, and installed a round, cylindrical, type of button switch in the housing.
Then all that i had to do was use the push on, push off, knob, to activate the switch, to kill the coil.
Always worked well, and it was a hidden kill switch, that you wouldn't know anything about.
Click to expand...
LOL......Great idea, but now I need to worry about the FABO guys. :lol:
 
That is not going to work as shown. The ignition, or ACC both go dead in "start." Seems to me overly complicated, just use a switch "somewhere." What do you have for a setup? EFI? Electric fuel pump? MSD ignition? Lots of ways to add a switch and they won't take time to find it.

If they show up with a roll back and a winch you are screwed, anyhow
 
My only comment, search for a real German made Bosch relay.. Allot of the stuff available these days says Bosch but it ain't.... And the quality isn't even close..
 
hemi71x said:
Back in the dinosaur days when i owned a 71 Hemi GTX, and a 71 Cuda, those cars still came with a cigarette lighter.
I never smoked, so i never needed to use those lighters.
I wanted to install a hidden kill switch, as a theft deterrent.
I remove the "guts" from the back side lighter, and installed a round, cylindrical, type of button switch in the housing.
Then all that i had to do was use the push on, push off, knob, to activate the switch, to kill the coil.
Always worked well, and it was a hidden kill switch, that you wouldn't know anything about.
Click to expand...
That's brilliant.

When my Neon kept getting stolen, I looked into using a crank position sensor from a Neon which is a latching sensor. Mount it in the dash and pass a magnet over it to turn on, pass again to torn off.
I never got around to actually doing it though. I just started pulling a fuse and taking it with me.
 
Wire the white wire of an electronic distributor fed MSD to a ground switch, that thing will never start. Give the MSD some time and it wont start either! Flame me......I had a Carter electric pump on my 65 back in the day and I had to turn it on manually. Forgot it and the car started sputtering 1/2 block down the road, hit it and it picked right back up.
 
273 said:
That's why i think a self latching relay is the way to go, you'd turn the key to the ACC position then push the button one like hemi71x described would be kool which would arm/latch the relay then turn the key to start, but everytime you turn the car off it unarms/unlatches and needs to be armed everytime the key is turn to the off position. Stopping the need to turn off the kill switch everytime which I'd would usually forget to do.

View attachment 1716012788
Click to expand...

Pretty sure that's what the switch under the hood was for on the seat belt interlock. Turn the key on and then pop the hood and push the red button and the relay would latch and allow the start circuit to work without the seatbelts being latched. Turn the car off and the relay unlatched and required the button to be pushed again.
 
The thing is, if there is any power under the hood at all it only takes about 4 feet of wire to start the car unless it is something like removing the coil wire or similar.

Doesn't mean it wouldn't slow someone down. They would probably need some time to figure it out unless they came knowing you had a kill switch.

I went with a battery disconnect myself.

Painless disconnect

Battery relocated to trunk, inertia switch?

Here is one I didn't use but there is a link to a place that sells one if you wanted ideas on how to wire it.

[FOR SALE] - 110 Amp Latching Relay
 
jos51700 said:
When my Neon kept getting stolen, I looked into using a crank position sensor from a Neon which is a latching sensor. Mount it in the dash and pass a magnet over it to turn on, pass again to torn off.
Click to expand...

I played with similar ideas.

Thought about a magnetic switch with a circuit that was open if the magnet wasn't in place. Something hidden next to the seat, and a fob that could be placed in the right spot when you got into the car kind of subtly. Then I decided that I didn't want to have to order new ID and credit cards every couple of weeks because the magnet kept erasing them.

I know there are RFID kits out now, too. Seems like it would be a similar arrangement without having to carry a magnet around in your pocket.
 
My RIP engineer buddy was, like me, a radio amateur. He was also a Maritime radio operator for Scripps Institute of Oceanography. He could "copy" CW (Morse Code) in his head at about 45 WPM.

Anyhow, in the early 70;s he built himself a decoder that read the brake light switch electrical output. In order to start the truck, you had to send a couple of letters, slow, with your foot in Morse

On a side note, "Q" codes, shorthand entended for CW/ Morse use, also have "fun fake" ones

One of my favorites was QBS? Which means "Are you full of Bull Sh*t?"

The answer, "R" for "roger" is "Yes, I am full of Bull Sh*t"

But the one that fits THIS story is "QLF?" which means "are you sending with your left foot?"

qlf.jpg
 
DionR said:
The thing is, if there is any power under the hood at all it only takes about 4 feet of wire to start the car unless it is something like removing the coil wire or similar.

Doesn't mean it wouldn't slow someone down. They would probably need some time to figure it out unless they came knowing you had a kill switch.

I went with a battery disconnect myself.

Painless disconnect

Battery relocated to trunk, inertia switch?

Here is one I didn't use but there is a link to a place that sells one if you wanted ideas on how to wire it.

[FOR SALE] - 110 Amp Latching Relay
Click to expand...
I'm rewiring the whole car the battery and fuse blocks and relays will be in the trunk, under the hood will be very minimal wiring. Was thinking of run two kill switches fuel pump and starter relay hidden in different spots, plus thinking of a way to use some kind solenoid to lock the ratchet shifter in park.
 
Too technical for me to follow.
Why not just install a switch in the iginition circuit ? Use a flasher switch that matches your year and model . Thats what I used for my electric fuel pump and 3 step burnout rpm limiter.
 
67Dart273 said:
Lots of ways to add a switch and they won't take time to find it.

If they show up with a roll back and a winch you are screwed, anyhow
Click to expand...
If relies on me to shut it off every time I'll forget to Making it pointless :)

If they tow it guess it's theirs.
 
273 said:
I'm rewiring the whole car the battery and fuse blocks and relays will be in the trunk, under the hood will be very minimal wiring. Was thinking of run two kill switches fuel pump and starter relay hidden in different spots, plus thinking of a way to use some kind solenoid to lock the ratchet shifter in park.
Click to expand...

My thought was that if there was anything hot under the hood, it could be used to bypass any kill switch you set up. So, for example, if the alternator wire is hot when the car is turned off (like it is stock), a wire from there to the ballast resistor and a quarter to cross the posts at the starter relay would be enough to start the car. Certainly there are other issues to address before someone could drive the car away, but it is the bigger part (in my mind). And relocating the starter relay would mean reaching down and crossing it at the starter lug, but still do-able.

Had a local guy get his Demon stolen out of his garage and as I recall, the security video he had showed something exactly like the above method.
 
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273 said:
If relies on me to shut it off every time I'll forget to Making it pointless :)
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I use a fob and it makes it kind of like most 90's cars anymore where you lock it as you walk away.

If I ever put power door locks in the car, hopefully I can set it up to set the alarm and disconnect the battery all at the same time so I can lock it as I get out and not have to lock it as I walk away.

I know the setup I have right now can be triggered to have a delay of some seconds after setting it if the door is open. Not sure on how to set up power locks to do it, I've got many other projects to finish before I even think about that one.
 
DionR said:
I use a fob and it makes it kind of like most 90's cars anymore where you lock it as you walk away.

If I ever put power door locks in the car, hopefully I can set it up to set the alarm and disconnect the battery all at the same time so I can lock it as I get out and not have to lock it as I walk away.

I know the setup I have right now can be triggered to have a delay of some seconds after setting it if the door is open. Not sure on how to set up power locks to do it, I've got many other projects to finish before I even think about that one.
Click to expand...
I looked into fob's how I came across self latching relay, like the door lock battery idea, get a four door solenoid set use one of the extras on a cutoff switch plus probably rig a shifter lock with the other one.
 
I used a simple toggle switch that cut the power to the starter, hidden under the dash. Took me a while to get into the habit, but I would switch on to start, then back off once running, granted that the car could still be hot wired or towed, but I always felt that if someone wanted something bad enough, they will find a way, no matter what I do.
 
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