What Wire to use to install a security toggle switch

[1Rad1955]

I would like to install an ignition cut off security switch on my 1991 GMC Sierra 1500. I noticed a pink wire coming out of coil to the back of the distributor. Any issues using this wire to cut off power to distributor? Also what Amp toggle switch should I use? Thanks in advance for your input to my questions!

 

[GoToGuy]

What does the wire do?

 

[Frank Enstein]

I recommend interrupting the wire the wire going to the coil from the ignition switch or better yet adding a wire from the negative side of the coil (the grey or white wire that runs the tach).

That way all of the wiring you add will be under the dash.

The advantage of grounding the coil is even if someone "hot wires" it it still won't start and there isn't a break in the wire going to the coil.
If the switch breaks the engine will still run.

However you decide to do it 14 gauge is enough, but I would use 12 gauge for dependability.

 

[F4U-1A]

When I took delivery of my new truck in 96, I tied into the clutch switch under the dash, Engine would not turn over, mine you if you got in and rolled down a hill it could be started. So I would replace the fuel pump relay with a dummy, if I thought the situation called for it. That was a long time ago, the 5sp alone is a deterrent now and the snow in the winter.

 

[smdk2500]

the 5sp alone is a deterrent now

Ahh gotta love the millennial anti theft device.

 

[LC2NLS6]

Ground based relays, less wires hot to deal with if they chafe and hit metal. Ie, put a ground interrupt on the fuel pump relay is an easy one. If you want to be cleverer, wire up a timer based relay so it runs for 5 seconds only then trips, but they are more expensive than a one wire toggle round trip to break a circuit.

You could also require power on a switch, like say, you have to turn the dome lights on to trigger a relay in the path of the trigger for the relay of fuel or ign...Then even if they find a toggle switch, its a rats nest of wires to figure out other stuff. Also, make every wire the same color.

 

[PlayingWithTBI]

put a ground interrupt on the fuel pump relay is an easy one.

Yep, it's better to cut fuel than ignition. This way you won't flood (or even hydro-lock) the engine cranking all that time.

 

[stutaeng]

What about tapping into the starter solenoid wire?

I picked up a wiring harness for my project truck and saw some wires connected there near the starter going into the cab. When I got home I realized that it was most likely a kill switch inside the cab.

 

[thegawd]

that starter solenoid wire is also under the dash. good idea.

 

[LC2NLS6]

Could also rewire the starter with a remote solenoid to the battery or somewhere hidden, that way you don't have a hot wire to the starter 100% of the time, the starter main wire only hot when cranking (race cars do this so they don't have a hot wire running the length of the car from a battery in the trunk).