Circuit Operation

Battery voltage is applied to the "BRAKE" Warning Indicators when the Ignition Switch is in "RUN," "BULB TEST" or "START." Several switches are connected to the "BRAKE" Warning Indicator. When any one of these switches close, ground is provided and the "BRAKE" Warning Indicators light.

The Ignition Switch provides a ground when it is in "BULB TEST" and "START" to light the "BRAKE" Warning Indicators.

The Park Brake Switch provides a ground when the Park Brake is applied. The "BRAKE" Warning Indicators light to alert the driver.

The Brake Pressure Differential Switch closes to light the "BRAKE" Warning Indicator when there is low brake pressure in one of the two hydraulic brake systems. This could be caused by a leak in one of the brake lines or a faulty Master Cylinder. The switch is reset to an open condition when brake pressure is restored.