Safari Van AWD V6-4.3L VIN W (1996)
Brake Warning Indicator: Initial Inspection and Diagnostic Overview
Circuit Operation
Battery voltage is applied through the GAUGES FUSE 4 to the Brake Indicator when the Ignition Switch is in the RUN, BULB TEST or START
positions. The Brake Indicator can be lit by having ground applied to it from any of three switches or the Brake Pressure Modulator Valve (BPMV).
The Brake Indicator will light whenever the Parking Brake is engaged. When the parking brake is engaged, ground is supplied through the closed
contacts of the Park Brake Warning Switch to the Brake Indicator. The Brake Indicator lights to alert the driver that the park brake is engaged.
The Brake Indicator will light when the Ignition Switch is turned from the LOCK to the RUN position. This is when the Brake Pressure Modulator Valve
(BPMV) conducts its initial test which entails lighting the Brake Indicator and the ABS Indicator. The Brake Pressure Modulator Valve (BPMV) will
also light the Brake Indicator if there is a malfunction within the Four Wheel Antilock Brake System which is affecting the operation of the base
hydraulic braking system.
The Brake Indicator will light if there is low brake fluid pressure in the Front or Rear Brakes. When the Brake Pressure Warning Switch senses low
brake fluid pressure in the Front or Rear Brakes it closes the Brake Pressure Warning Switch. A ground is supplied through the closed contacts of the
Brake Pressure Warning Switch to the Brake Indicator. With both power and ground applied to the Brake Indicator, it will light.
If the vehicle is equipped with Daytime Running Lamps (DRL), then there is an Ignition Switch BULB TEST function that will light the Brake Indicator
whenever the Ignition Switch is turned to the BULB TEST position.
Troubleshooting Hints
1. CHECK condition of GAUGES Fuse 4. If Fuse is Open, LOCATE and REPAIR source of overload. REPLACE Fuse.
2. CHECK that grounds G104 and G105 are clean and tight.
3. CHECK the Brake Indicator bulb for an open filament.
4. CHECK that the Parking Brake is fully released.
5. Make sure that there is an adequate amount of brake fluid in the reservoir.
^ CHECK for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove GOOD in a
Continuity/Voltage check with a system disconnected. These circuits may be intermittent or resistive when loaded, and if possible, should be
checked by monitoring for a voltage drop with the system operational (under load).check for proper installation of aftermarket electronic
equipment which may affect the integrity of other systems (See Diagnostic Aids for General Troubleshooting Procedures). See:
Diagrams/Diagnostic Aids
