Will Water on the Car Floor Affect the Internal Wiring?
3 Answers
If water ingress in the vehicle is not promptly addressed, accumulated water can easily cause short circuits in some wiring under the floor. This can affect the normal operation of the vehicle when starting it, and may even burn out the onboard computer, leading to vehicle malfunctions. Below are other hazards of water ingress on the car floor: 1. Rust and corrosion of the vehicle. If water on the vehicle floor is not treated in time, the water can corrode the floor and metal components, causing floor damage and rusting of metal parts, significantly increasing the likelihood of vehicle malfunctions and threatening the safety of the driver. 2. Unpleasant odors in the vehicle. If water is not promptly removed and dried after ingress, residual water can corrode the vehicle floor and cause the floor mats to mold and deteriorate, emitting foul odors and resulting in unpleasant smells inside the vehicle.
Last time I encountered a situation where my car was flooded after a heavy rain, with water reaching the level of the floor mats. I was particularly worried about the wiring under the floor, as there are airbag sensor harnesses under the seats and window control wiring along the four door sills. Water accumulation can cause oxidation and rust on connector pins, potentially leading to signal transmission issues and jerky window operation. Even worse, water-soaked harnesses can develop mold, and the gradual corrosion of copper wires can result in poor contact. That time, I quickly removed all the floor mats to dry them for three days and had a mechanic use a multimeter to test the circuit resistance. Fortunately, I caught it early, and no major issues arose. Now, after every rain, I check the carpets for any moisture, as electronic components are most vulnerable to water damage.
As a veteran driver who frequently works on construction sites, muddy water seeping into my car's floor is a common occurrence. Electrical issues always seem to pop up after rain—suddenly, various warning lights appear on the dashboard, or the window switches stop working. After peeling back the floor mats, I discovered the wiring harness soaked black, with connector pins covered in green corrosion. The wiring under the car may look protected by rubber casings, but prolonged exposure still lets water seep in. For instance, brake light wires and turn signal wires run inside the sill panels. Once, floodwater reached the seat rails, triggering the airbag warning light—costing over 800 yuan in repairs. Now, I always keep absorbent towels in the trunk. If water gets in, I immediately remove the seats and lift the carpets, using a hairdryer on the cool setting to dry the wiring harness connectors. After all, replacing water-damaged electronic modules is far too expensive.
