The controls in the Model AA are entirely mechanical, except the windshield wipers in later models. The brakes are mechanical and the truck has four oversized drum brakes to stop the vehicle. The mechanical system is a pull lever system that applies the force from the pedal to a pivot that pulls the brake rods that expand the brakes in the drums. The brake light is activated when the brake pedal is pushed. The brakes are proportioned more toward the rear drums. The parking brake is a chrome lever on the floor with a release button on the top. The windshield wipers started as hand operated and later models were powered by vacuum diverted from the intake manifold. The horn button is mounted in the middle of the steering wheel assembly. Controls for the lights are also incorporated into the steering assembly. The switch was a three-stop switch for parking lights, headlights and high-beams. The tail-light lens colors on the AA underwent several changes during the production run. Two levers are mounted on the steering column to adjust the engine. The left lever controls the manual advance and retard of the timing. Adjusting the timing of the engine changes the time that a spark will occur in the combustion chamber and those changes affect the performance of the engine. The right lever is a manual control for the throttle. The throttle can be adjusted to ease the shifting of the transmission and the idling speed of the engine. Underneath the dash on the right side is the choke rod. The choke can adjust the flow of fuel from the carburetor into the engine. Turning the knob on the choke rod clockwise closes the fuel flow, leaning out the engine; turning the knob counterclockwise opens the fuel flow to the engine.