What should a mechanic test for water leak?
A useful test plan for water leak verifies the operating state first, preserves scan evidence, and measures the competing body & accessories paths before any component is replaced.
Plausible causes
- Body control, accessory, harness, or water-intrusion concern
- Local motor, switch, latch, camera, or module path
- Shared supply, network, chafe, or water intrusion
Useful next checks
- All-module scan including U-codes and low-voltage history
- Loaded feed/ground and network-topology tests
- Controlled harness/connector pin-fit, chafe, and corrosion inspection
- Sectional water test and source repair before module replacement
Sources and method
This answer provides hypotheses and a verification plan, not a component verdict. Exact repair procedures require authoritative service information for the specific vehicle.
Intermittent Electrical Concerns from Harness Chafing · NHTSA / General Motors