Ignition switch bypass circuit

An ignition switch bypass apparatus for a motor vehicle, the motor vehicle having a battery, an ignition circuit, and accessory circuit, and an ignition switch activated by a key, comprising:

• a relay having a coil and multiple sets of contacts connected to the ignition circuit, the accessory circuit, and the battery, one end of the relay coil coupled to the ignition switch;
• a pushbutton switch coupled to the other end of the relay coil and operable to energize the relay coil to connect the battery to the ignition circuit, accessory circuit, and relay coil while bypassing the ignition switch, thereby allowing the key to be removed from the ignition switch with the motor vehicle continuing in operation;
• an inhibitor switch in series with the relay coil that prevents the motor vehicle from being started in gear, the inhibitor switch changing state to de-energize the relay coil and disconnect the battery from the accessory circuit, ignition circuit, and relay coil if an attempt is made to put the vehicle in gear;
• and
• a first switch coupled between the relay coil and ignition switch, the first switch opening to de-energize the coil in response to detection of low oil pressure or overheating of the motor vehicle.

An ignition switch bypass apparatus for a motor vehicle, the motor vehicle having a battery, an ignition circuit, and accessory circuit, and an ignition switch activated by a key, comprising:

• a relay having a coil and multiple sets of contacts connected to the ignition circuit, the accessory circuit, the starter circuit and the battery;
• a transistor coupled to the ignition switch and to one end of the relay coil, the battery supplying current to the transistor for the coil through the ignition switch;
• a push button switch coupled to the other end of the relay coil and operable with the transistor to energize the relay coil to connect the battery to the ignition circuit, accessory circuit and transistor while bypassing the ignition switch, thereby allowing the key to be removed from the ignition switch with the motor vehicle continuing in operation;
• an inhibitor switch that changes state to de-energize the relay coil and disconnect the battery from the accessory circuit, ignition circuit and transistor if an attempt is made to put the vehicle in gear;
• and
• a switch coupled to the transistor which changes state in response to a change in oil pressure in or overlapping of the motor vehicle to disable the transistor and thereby de-energize the coil.

An ignition bypass switch for a motor vehicle having a battery, an ignition circuit, and a key - activated ignition switch, comprising:

• a bypass switch means which bypasses the ignition switch for connecting the battery to the accessory and ignition circuits,
• a driver actuatable switch,
• sensor means sensing at least two of placing the vehicle in gear, engine overheating, and oil pressure loss, and
• control means receiving the driver actuable switch and the sensor means as inputs and controlling the bypass switch means such that the bypass switch means is closed or made conductive in response to actuation of the driver actualable switch and the bypass switch means is opened or made nonconductive in response to the sensor means sensing at least one of placing a vehicle in gear, engine overheating, and oil pressure loss,
• wherein a driver may remove a key from the ignition and have the vehicle remain in a running condition.