B1431

Step 1: Perform visual inspection of wiper relay location, check for corrosion, melted terminals, or physical damage. Remove relay and inspect socket for signs of overheating, corrosion, or bent pins.

Step 2: Using a multimeter, test the relay coil resistance (typically 70-120 ohms) and perform bench test by applying 12V to coil terminals while checking for continuity across switch contacts. Replace relay if faulty.

Step 3: With relay removed, use multimeter to verify 12V battery power at relay socket power terminal and check for proper ground circuit continuity (less than 1 ohm resistance to chassis ground).

Step 4: Backprobe BCM connector while monitoring relay control signal with multimeter or test light during wiper operation. Voltage should switch between 0V and 12V. Check all related wiring for shorts to ground or power, open circuits, or excessive resistance (compare to wiring diagram).

Step 5: Disconnect wiper motor connector and measure motor current draw with ammeter during operation (typical draw 3-6 amps). Excessive current indicates internal motor fault causing circuit overload.

Step 6: If all circuits and components test good, suspect BCM internal fault. Verify BCM software is up to date, clear codes, and perform wiper system functional test. Replace BCM if fault returns and all other components verified good.