1990 Ford Bronco "90 silverado ignition switch" Questions

...silverado 1500 and the starter engages whenever the battery is hooked up i been told the ignition switch any ideas where that is or what it could be i had the same problem on my 90 half ton, it is ...

90 3500 chevy switch ok can't fine a fuse for headlights there is no fuse for the headlights, there is a built in circuit breaker in the main headlight switch, it gets power directly from the ignition