Forum Discussion
mike-s
May 24, 2017Explorer
A diode (like the common 1N4001), and a buzzer, wired like this. During normal driving, the brake lights come on when you're braking, so the brake circuit is never at a higher voltage than the brake light circuit and the diode will keep the buzzer from sounding. When disconnected from the vehicle, there's a path to ground via the brake lights. If you have LED brake lights, you'd need a low current buzzer.
You could even eliminate the buzzer (would need at least a 5 amp diode if your brake lights use bulbs), your brake lights would come on when the pin was pulled.

You could even eliminate the buzzer (would need at least a 5 amp diode if your brake lights use bulbs), your brake lights would come on when the pin was pulled.

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