Electric opening and closing of car windows consumes a lot of power. The moment of activation in idle mode may even cause the engine sound to change. Therefore, for cars with weak batteries, be careful not to open or close the windows at the same time. 1. The reason why the electric window does not operate smoothly is mostly because the oil in the lift inside the door is exhausted. The inner cover should be removed and oiled. 2. If the glass fails to move at all, the switch may be faulty. If the switch is faulty, it can only be replaced. 3. If the electronic device does not operate, it is common sense to check the fuse. Double check which fuse is for the power windows. 4. When the operation of the switch deteriorates and the car window cannot be opened smoothly, the possibility of switch failure is very high. 5. Before refueling the internal mechanism, first remove the inner cover. Remove the hidden screws and remove the snap-action switch. 6. Remove the inner cover and peel off the waterproof plastic paper underneath to expose the window lift mechanism. 7. Spray grease on the arm fulcrum and the inside of the gear. By moving it up and down while spraying, you can coat even the smallest parts. 8. The slider parts that support both ends of the glass also need to be inspected. When the sliding condition between glass and thermal conductivity is poor, brightener can be applied. 9. In order for the glass to slide smoothly, it is important to minimize resistance. The stain on the glass will also become a resistance, so the windows should be kept clean at all times.