What to Do When a Car's Electrical Circuit Gets Wet
2 Answers
Disconnect the negative terminal of the battery as soon as possible to prevent short circuits in various electrical components due to water exposure. Water ingress can cause the connecting rod to bend, damaging the engine. Water in the engine oil can lead to oil deterioration, causing excessive engine wear. If the car's electronic control unit (ECU) gets wet or damp, it must be removed in the shortest possible time, and surface moisture should be wiped clean.
I've dealt with similar issues before, and water in the electrical system is no small matter. Remember, the first thing to do is safely pull over and turn off the engine, then disconnect the negative battery terminal to prevent short circuits or fires. Next, check the source of the water—whether it's from leaving the door slightly open after rain or leaks in the engine compartment—and quickly dry the electrical connectors with an absorbent cloth. If there's only a small amount of water, you can let it air dry in the sun for a few hours, but don't rush to start the engine, or you risk frying the ECU. I once saw a car where the owner tried starting it after water got in, resulting in a repair bill of over ten thousand for the computer board. It's a good idea to keep some desiccant packs in your car and remind car wash attendants not to spray water near the electrical boxes. If the situation is severe, have it towed to a professional shop immediately. The technicians will use compressed air to thoroughly dry everything and check for any damage to fuses and relays.
