How can you tell if a converter dolly has anti-lock brakes? Question How can you tell if a converter dolly has anti-lock brakes? Answers There will be a sticker displaying the letters "ABS." There will be a plaque containing information on the side of the dolly. There will be a yellow lamp on the left side of the dolly. There will be a blue light on the side of the dolly. Explanation A converter dolly equipped with an Anti-Lock Braking System (ABS) is required to have a yellow lamp on its left side.