TEST 39C - Repairing Brake Warning Light & Brake Pressure Switch Problems
NOTE:
For connector terminal identification, see CONNECTOR IDENTIFICATION. For wiring diagram, see WIRING DIAGRAMS at the end of this article. Perform VERIFICATION PROCEDURE VER-1 after each repair.
CAUTION:
Always turn ignition switch to OFF position prior to disconnecting or connecting any module connector.
- Observe brake light on dash while cranking engine. Turn ignition switch to RUN position. If brake warning light does not illuminate, go to step 4). If brake warning light illuminates, go to next step.
- Disconnect brake pressure warning switch connector. Check, clean and repair connections as needed. Connect jumper wire between brake pressure warning switch connector Gray/Black wire and ground. If brake warning light illuminates, replace brake pressure warning switch. If brake warning light does not illuminate, go to next step.
- Disconnect instrument cluster Red connector. Using an external ohmmeter, measure resistance between instrument cluster Red connector terminal No. 5 (Gray/Black wire) and brake pressure warning switch connector Gray/Black wire. If resistance is less than 5 ohms, replace instrument cluster. If resistance is more than 5 ohms, repair open Gray/Black wire between instrument cluster Red connector and brake pressure warning switch connector.
- If brake warning light does not illuminate in step 1), turn ignition switch to OFF position. Disconnect ignition switch connector. Check, clean and repair connections as needed. Connect jumper wire between ignition switch connector terminal No. 3 (Gray/Black wire) and ground. Observe brake warning light on dash. If brake warning light illuminates, replace ignition switch. If brake warning light does not illuminate, go to next step.
- Disconnect instrument cluster Red connector. Check, clean and repair connections as needed. If brake warning light does not illuminate, repair open Gray/Black wire between ignition switch connector and Red instrument cluster connector.