These little guys are seemingly everywhere on the Interceptor. On the Mk2s & Mk3s they live under your brake pedal and provides illumination to your brake lights in the rear. It also lives in your fuel system activating a warning light for the fuel flap and handbrake warning. Mk1s have a keyed fuel flap and the stop light switch lives in a different location but doesn't have to. Oh, those Mk1s, their Stop Light Switch lives in-line in the braking system! (very messy) For Mk1s, please email or call and we'll fix you right up with the proper gear.