The low-voltage wiring harness of a car connects various electrical devices on the vehicle, plays the role of power distribution and signal transmission, and is the nervous system of the car. In order to ensure the stability of the wiring harness system operation, it is necessary to combine the operating environment of each area of the vehicle and recognize the corresponding protection plans that should be adopted for the wiring harness in each area.After the terminal is riveted with the wire harness, the sealing lip is scratched when the waterproof plug of the equipment is damaged due to the poor riveting of the terminal; The orientation of the waterproof plug and the wiring harness equipment is wrong; The waterproof plug has caused damage in front of the device; Poor orientation of the male/female sealing ring equipment, and the sealing ring is warped;Poor design of the interference between the sealing ring and the wiring harness; Poor planning of the interference between the sealing ring and the mother body of the receptacle; The designed interference between the male end and the female end waterproof plug is poor; The designed interference between the female end and the waterproof plug is poor;Using this inspection method for assemblies that can be pressed without damaging the assembly (for example, having a drain header connector, etc.), the leak rate is defined as zero. Samples should be pressurized (default 48 kPa (7 psi) above ambient pressure) at room temperature and submerged at water temperature for at least 5 minutes always looking at foam flow on each side.Modeled on thermal shock caused by cold water, for parts in cars that can be splashed with water. The intent is to mimic the eruption of cold water on a thermal system/component, like a sedan trudging through wet roads in winter. The failure mode is due to the different expansion coefficients between the materials, causing mechanical rupture or sealing failure of the materials. Requirements: The inspection samples can work normally during and after the inspection. No water entered the sample. In order to examine the effect of dust, this effect has been increasing over the years on vehicle operation. For example, the collection of dust in electronic control units, and the humid environment, can create conductive loops on unpainted circuit boards. Dust buildup can impair the functioning of mechanical systems, such as moving parts that are connected to each other. Vibration can have a conflicting effect on parts that mask dust. Requirements: The test sample should operate normally during and after the test. In addition, the test sample should be removed for inspection to ensure that no appreciable dust is generated, which may cause defects, or may cause electrically conductive connections when wet.