Single Relay Passive Starter Kill?

will this work?

one realay

87 -key side of starter

86 -ground

85 - 12 volt jumped power source (in ex) volume up button, or sunroof close button . that when toggle is hit in the specified direction the wire will be powered and then trigger relay.

30- motor side of relay

i want a single relay basic setup for a starter power kill that will utilize a existing momentary button already in the car.

any suggestions?

That should work if you only want to be able to start your car when the ignition is on and you activate the switch. It will be kind of hard to turn the key and activate the sunroof switch at the same time though. Why don't you try this instead:

#85 to 12V constant or ignition

#30 to starter side of start wire

#87 to Key side of start wire

#86 (-) to the seat belt switch when plugged in.

This way your car will only start when your seatbelt is plugged in. How many theives are going to buckle-up when they're stealing a car, especially if the car won't start.

Don't forget, everything you do doesn't mean jack if the wires are easy to find.

I have two ways of doing these-----does the switch you wish to use in your car make a negative or positive?

If you have a positive switch (parking lights, high beam, brake):

86: ignition

85: parking light wire

87a: starter input

30: starter output

When the parking lights are off, the wire has what looks like a ground---it's kind of a crappy ground, but that doesn't matter----it's plenty strong enough to trigger the relay, preventing the car from starting.  When the parking lights are switched on, both sides of the relay coil see 12 volts---meaning the relay is switched off---meaning the car is allowed to start.  Also, this is a normally-closed starter kill----if the relay should fail, the car will probably still start.

If the switch in your car has a negative output  (power mirrors, cruise buttons, turn signal switch):

85 to cruise button

86 to ground

87 starter input

30 starter output

This is a normally-open starter kill--- a little more secure, but also a little less reliable should the relay fail.

A few other notes:

1.  In either of these setups, you'll likely have to remove the diode that is on the harness of most starter kill relays.

2.  Make sure you tie into a seldom-used switch for this setup, because the relay is going to trigger every single time you use the switch.  It would be annoying to hear the relay clicking on and off every time you step on the brakes or operate your cruise control-----on the other hand, you probably almost never use your power mirrors.  Also, avoid using the parking lights---you're likely to forget and leave them on when you get to your destination, and you'll kill your battery.

3.  If you go for the power mirror switch, test carefully.  The operation of the power mirror system is somewhat complex, but we don't need to know the details of it.  Just remember that different wires have different functions, depending which way you move the adjustment buttons, and whether you have the control switch in the left, right, or off positions............if you take your time and test carefully, you will surely find a wire that always makes a positive when you push the button in one direction, regardless of how the control switch is set..... and you'll find another wire that always makes a negative no matter what.