B1465

Step 1: Locate the wiper brake/run relay in the fuse/relay box (typically under hood or dash) and visually inspect for corrosion, burnt contacts, or physical damage. Check related fuses for continuity using a test light or multimeter.

Step 2: Remove the relay and test relay coil resistance across control terminals (typically 70-120 ohms). Apply 12V directly to relay coil terminals and verify audible click and continuity across load terminals using multimeter.

Step 3: With relay removed, check for battery voltage at relay socket power terminal (key on). Then backprobe BCM connector to verify ground side control circuit has less than 1 ohm resistance to relay socket using multimeter in continuity mode.

Step 4: Using a multimeter, check BCM relay driver output by commanding relay activation through scan tool bidirectional controls (if available) while measuring voltage at BCM output pin - should switch from 12V to ground when activated.

Step 5: Inspect all connectors in circuit for pushed-back pins, corrosion, or moisture. Wiggle test harness while monitoring circuit continuity. Check BCM ground connections for proper contact and less than 0.5 ohms resistance to battery negative.

Step 6: After repairs, clear codes, cycle wipers through all positions (off, intermittent, low, high, park), and verify relay operation. Road test and rescan to confirm no code returns.