Brake Warning Indicator: Description and Operation

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

The Ignition Switch provides a ground when it is in 'BULB TEST" and "START." The BRAKE" Warning Indicator lights.

The Park Brake Switch provides a ground when the Park Brake is applied. The "BRAKE" Warning Indicator lights 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.

The Brake Fluid Level Switch closes to light the indicator when brake fluid is low. A diode is included in this circuit to isolate the EBCM from the other brake warning devices.