Water dripping from a car when the air conditioner is turned on is a normal occurrence and typically indicates that the air conditioning system is functioning properly. The water is actually condensation that forms on the evaporator coil inside the air conditioning system.
Here's how it happens:
The air conditioner cools the air: The air conditioning system cools the air by passing it over the evaporator coil, which is located inside the car's dashboard.
Moisture in the air condenses: As warm air passes over the cold evaporator coil, the moisture in the air condenses into water droplets on the coil's surface. This is similar to how moisture forms on a cold glass on a hot day.
Water drips from the coil: As the condensation accumulates on the evaporator coil, it eventually drips down and collects in a drain pan. From there, it is directed through a drain tube or hose that typically leads to the exterior of the car.
Water exits the car: The water exits the car through a small drain tube, usually located on the underside of the vehicle. It is not uncommon to see water dripping or pooling underneath the car while the air conditioner is running.
If you notice a significant amount of water or if it appears to be leaking inside the car rather than draining outside, it could indicate a clogged or damaged drain tube. In such cases, it is advisable to have the air conditioning system inspected and serviced by a professional mechanic to ensure proper drainage and prevent potential issues.