Deactivator Switch
On vehicles with speed control, a deactivator switch is located underneath brake master cylinder as an additional safety feature. See Fig 1. Normally, when brake pedal is depressed, an electrical signal from brakelight circuit to speed control amplifier will turn off system. Under increased brake pedal efforts, deactivator switch mounted on master cylinder will open and remove power to speed control actuator clutch, releasing throttle independent of speed control amplifier.