I'm guessing that you have an electronic engine, for the year 2000. There is a good chance, for its brake pedal ECM signal, it might just be using a simple air pressure switch, set at 3-5 psi that triggers an "Closed" circuit  "Open Circuit"   (with brake pedal depressed) = that tells the ECM, on the engine, that the brake pedal is depressed.

 It may not have anything to do with 12 volts DC ,at all. 

 It might just be "closing a circuit". "opening a circuit"

Hopefully, Bern will read this thread, and add more info.

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Edit: I am a little unsure , if this is the correct electrical engine schematic, for your engine. I do know it is for a CAT engine, that has a 70 pin design, ECM on it.{found photo of a schematic, on a PTO installation blog}

Notice what it shows for the brake pedal = closed circuit means brake pedal released. ( So, I assume, you must have a sensor, that is open, or broken wire, or some air pressure is telling OEM sensor to "open up" = thus it is "telling" ECM that the brake pedal is depressed)