Can Stop/Turn Circuit be Used for Stoplight Circuit for Supplemental Braking System

Question:

I have a 2004 Honda CRV flat towed behind a motorhome. The wiring harness in the Honda is a standard 4 wire straight from the MH to the Magnetics lights. No connections to the existing wiring For activation of my Add -a-Brake Braking System I need a signal from the Brake lights. Can I splice a line into the green or yellow wire? Do I need to put a diode in any of the lines. Thanks for your assistance

asked by: Frans L

Expert Reply:

Since the stop light circuits you mentioned wanting to tap into also carry the turn signal circuit you cannot use them for the brake light activation of your supplemental braking system. You'd need to tap into a dedicated stoplight circuit which you'd find at the brake pedal. Use a circuit tester like part # PTW2993 to test the wires that run to the brake pedal switch till you find one that only has voltage when the brakes are applied.

expert reply by: Jameson C