The reasons for the water in the wiring harness are generally as follows:
1. Unreasonable connector selection
The general application environment of the automotive wiring harness is divided into a wet zone and a dry zone. The wet zone generally refers to the exposed part. Conventional automotive wiring harness belongs to this category except for the dashboard wiring harness in the car body cabin. The connector of the wire harness in the wet zone must choose the connector above the requirement of waterproof grade IPX7; If the water-resistance of the selected waterproof connector fails to reach the grade, the vehicle is easy to get water after working in the wet zone environment for a period of time; In addition, in order to ensure the waterproof connector's waterproof quality, the wire diameter of this type of connector should be checked accordingly. The wire diameter beyond the use range of waterproof connector should not be selected, and of course, the wire diameter smaller than the use range of waterproof connector should not be selected.
2. The wire design in the sheath is unreasonable
The wire of the waterproof connector is generally designed as a single wire, and the design of this type of connector is designed with a double piezoelectric wire (when the wire is double-pressed, there is a gap between the two wires), which causes the water to enter the waterproof connector.
3. Waterproof terminal crimping is unqualified
When the waterproof terminal is pressed, the waterproof bolt is damaged, and there is an obvious gap between the wire and the waterproof bolt after pressing; The incorrect pressing position of the waterproof bolt is forward or backward, which causes the damage of the waterproof bolt or the waterproof bolt is higher than the rear end face of the jacket.
The siphon originally refers to the phenomenon of squeezing the liquid in a tubular container with a high liquid level into a low liquid level by using the difference in liquid level under the action of atmospheric pressure; in the wiring harness, when wiring points, grounding points and other wiring harnesses require When the insulation part is not well sealed, water will be siphoned from a high place in the low position sealed connector in a humid environment such as the chassis wiring harness, causing water in the connector, short circuit, and electrical failure; in addition, due to the existence of automotive electrical appliances when working Temperature rise (such as when the headlights are working at night, the local temperature is higher), when the car stops working, the temperature rise and fall will cause the pressure difference between the two ends of the wiring harness to cause the water in the poor wiring harness connector in the humid environment to enter the waterproof seal connector.
The above information is provided by automotive harness manufacturers.