[Cp Rooks]

Does anyone know which wire goes from the push to start button, to the starter relay under the hood fuse box, in the harness under the steering wheel? I'm trying to install a killswitch

[arpad_m]

Here's the relevant schematic for you from the service manual, but note that this is a modern car, the start button isn't wired directly to anything, it's a pulse/hold signal source to the BCM. You can tap other wires, though, say, one of those that feed the starter motor.

Color coding is as follows:

BK  Black
BN  Brown
BU  Blue
GN  Green
GY  Gray
PK  Pink
RD  Red
VT  Violet
YE  Yellow
WH  White

[CalgaryZL1]

Originally Posted by arpad_m

Here's the relevant schematic for you from the service manual, but note that this is a modern car, the start button isn't wired directly to anything, it's a pulse/hold signal source to the BCM. You can tap other wires, though, say, one of those that feed the starter motor.

Color coding is as follows:

BK  Black
BN  Brown
BU  Blue
GN  Green
GY  Gray
PK  Pink
RD  Red
VT  Violet
YE  Yellow
WH  White

Thanks! This is perfect

[Cp Rooks]

Thanks. Going to have to change plans then, I thought maybe it would be directly connected. My coworker thinks there should be a bolted wire on the starter I can use so I don't have to cut any wires

[bishopts]

Originally Posted by Cp Rooks

Thanks. Going to have to change plans then, I thought maybe it would be directly connected. My coworker thinks there should be a bolted wire on the starter I can use so I don't have to cut any wires

its in the diagram. yellow wire on the starter motor.
2 wires go to the starter. one larger one smaller.
larger is constant hot from the battery
smaller is signal from the starter relay.

apply 12v to the signal wire and the starter will crank the engine over.
take the small wire and cut it in half. then the start signal can never get to the starter and it wont start. at that point you have interrupted the starter.

the way a kill switch works is you have a temporary bypass. you cut the wire and add it to your kill switch. then you put the other side of the wire on the kill switch. at that point if the switch is on it bridges them together. and if its off it creates an open circuit that doesnt let the starter get a signal.

aftermarket alarm, toggle switch, breathalyzer, passtime gps tracker. they all do this. create a hidden circuit interrupt that doesnt follow any kind of common form factor, one that you know how to bypass and no one else does.

on the starter you could unplug the signal wire without cutting it and wire in your interrupt there. you would need to feed your control wires into the cabin somewhere hidden and isolate the wires from contacting anything that will cause a short. it could be as simple as a lawnmower momentary start switch under the shift boot for the shifter.
when you press the start button the car will do its normal start procedure and look for the key, verify it, then tell the pcm to send the start signal. at that point the signal will be going down the harness to your interrupt button. you just press it and allow it to pass to the starter.