Replacing an Ignition With a Toggle Switchby Don Bowman
Replacing an ignition switch with a toggle switch is used primarily for race car applications or early model cars that do not have a computer-controlled engine management system. To modify a computer-controlled vehicle in this manner would require the key to unlock the steering wheel and an electrical nightmare to incorporate the security system, the computers, fuel injection, ignition and a multitude of other systems. The final result would be a thousand times more expensive than replacing the ignition switch and then would have no security at all.
This, however, is a preferred modification for race cars. If the car has a locking steering wheel, the key must be used unless the locking mechanism is removed. The battery must be disconnected prior to removing the switch.
Remove the ignition switch, leaving the key tumbler intact. Hold the ignition switch away from any metal that can act as a ground and reconnect the battery temporarily. Use a voltmeter and probe back of the switch for battery voltage. Once the terminal is identified, cut the wire and put a piece of tape on it or mark it some way to identify it as the hot wire. Purchase two 30-amp toggle switches, one of which should have a safety cover. This is not necessary, but is a good safety feature.
One switch will be an on and off switch for all accessories and engine ignition. The other is for the starter. The covered switch should be used for the starter. Attach the hot wire from the battery to the ignition switch top post. Attach the remainder of the wires, except for the yellow wire, to the opposite terminal of the ignition switch. Attach a separate wire from the battery terminal of the ignition switch to the starter switch. Attach the yellow starter wire to the opposite terminal of the starter switch. Install the switches in a location that is convenient, but where it is unlikely to be accidentally turned off.
To start the vehicle, turn the ignition key on to release the steering wheel and the transmission gear shift lock. Hit the ignition switch to start the engine. If the starter switch is not spring loaded the switch should be shut off as soon as the engine starts or the starter will stay engaged.