We found this circuit for immobilizing a car's ignition system in the December 1976 Radio Electronics magazine. The circuit uses the courtesy light activation switches.
The Buck-type DC-DC converter (voltage lowerer) shown in figure 11 is suggested by Analog Devices...
This circuit can be used to directly control direct current loads or higher alternating current loads...
This circuit can turn-on (only) a load (relay or lamp) when S1 is pressed. The circuit can be used as...