Testing Warning Light Switch Section

Attach bleeder hose to either rear brake and immerse other end of hose in container with brake fluid. Ensure master cylinder is full. Turn ignition to "ON", open bleeder screw while pressure is applied to brake pedal. Warning lamp should light. Close bleeder screw before pressure is released from pedal. Reapply pedal pressure (moderate to heavy). Light should go out. Repeat test on front system. Results should be the same. Turn ignition off. If lamp does not light on either system, but electrical circuit checked good, warning light switch portion of valve is defective.