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How to Wire a Kill Switch Between the Hei Distributor

by Robert Bayly

Modern cars and trucks are equipped with alarms, but that was not always the case. Since older vehicles do not come with alarms, many people like to add a hidden kill switch to their older vehicle as an added level of anti-theft protection. A kill switch simply provides a break in a critical circuit, usually the starter, or ignition circuit. In the case of a General Motors HEI ignition, a kill switch can easily be introduced into the power wire to the ignition coil.


Park the vehicle on a level, paved surface and set the parking brake. Make sure the ignition is turned off.


Locate the power wire to the ignition coil. You want the red wire that plugs into the "Batt" terminal on the ignition coil, which is located on top of the distributor cap. Find a suitable place to cut the wire, perhaps 6 inches back from the distributor. Do not turn on the ignition while performing this procedure. Use the wire cutter on an electrical crimping tool to cut the wire.


Use the wire stripper part of an electrical connector crimping tool to remove about one-fourth of an inch of insulation from each end of the power wire that you cut.


Slide a 14-gauge in-line butt connector over one end of the power wire. Use the crimping tool to crimp that end of the connector. Repeat this process for the other end of the wire. You now have a connector on each end of the wire with one end of the connector crimped and the other end open to accept another wire.


Decide where you want to mount your kill switch. It is a matter of personal preference. You can mount it in the engine compartment, under the dash inside the passenger compartment, or even in the fender well. You want a two-pole, on/off toggle switch rated for 10 Amps.


Mount the switch. Run two lengths of 14-gauge wire from the switch to where you cut the power wire. Use the crimping tool to strip about one-fourth of an inch of insulation from each end of each wire.


At the power wire,, connect one wire from the switch to one end of the cut power wire by sliding the end of the wire into the other end of the butt connector. Use the crimping tool to crimp the connection. Repeat this for the other wire. It does not matter which wire you connect to the ends of the power wire.


Move back to the switch. Use the crimping tool to crimp an insulated female spade connector to each end of the wires at the switch. The toggle switch has two male spade connectors on it. Push one wire onto a connector. It does not matter which wire goes on which connector.


Flip the switch into the "off" position to prevent the ignition coil from providing a spark to the spark plugs. Moving to the "on" position will allow current to flow to the coil, providing spark.

Items you will need

About the Author

Robert Bayly, based in Apple Valley, California, began writing in 2010, his "how to" articles can be found on eHow. With more than 15 years in the auto industry, Bayly has been an auto and diesel mechanic, service writer and parts manager. He received certificates from Pontiac (parts system), Cat Diesel (engine service), Saab and Fiat (parts- warranty system).

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