* BCM Location: The BCM in a 1994 Grand Cherokee is likely located somewhere relatively protected, but still susceptible to water intrusion if a substantial amount of water gets into the vehicle's electrical systems. Water can find its way into unexpected places.
* Electrical Shorts: Water is a great conductor of electricity. If water gets into connectors or wiring related to the BCM, it could cause shorts, leading to damage and malfunction. The BCM controls many things, including the door locks.
* Corrosion: Even if a short doesn't immediately occur, prolonged exposure to moisture can cause corrosion on electrical components over time. This gradual corrosion could eventually lead to failures like the one you're experiencing.
* Other Affected Components: Before blaming the BCM, consider other modules or components that might have been affected by the water. The problem might be closer to the door lock actuators themselves (which could have gotten wet). Water intrusion could damage other components in the electrical system before reaching the BCM.
What to do:
1. Thoroughly dry the engine compartment: Use compressed air to blow out as much water as possible from all crevices and connectors.
2. Check fuses: Inspect all fuses related to the door locks and power locks. Replace any blown fuses.
3. Inspect wiring: Look for any signs of water damage (corrosion, damaged insulation) on the wiring harnesses leading to the door locks.
4. Professional diagnosis: If you can't find any obvious issues, it's best to take it to a mechanic or auto electrician. They have the tools to properly diagnose the problem and determine if the BCM or another module is at fault. They can also use a scan tool to check for fault codes that will help pinpoint the problem's location.
In short, while it's not the most likely scenario, water intrusion *could* have played a role in the failure of your door locks. A professional diagnosis is recommended to determine the exact cause.
