Automotive wiring harnessIt is the main body of the automobile circuit. Without harness, there is no automobile circuit. With the increase of people's requirements for safety, comfort, economy and emissions, the car harness becomes more and more complex, but the space of harness becomes smaller and smaller. Therefore, how to improve the overall performance design of the automobile harness has become the focus of attention. The automobile harness manufacturer is no longer simply engaged in the design and manufacture of the harness, and it has become an inevitable trend to carry out the preliminary development work with the automobile main machinery manufacturer. Based on many years of harness design and manufacturing experience, talk about the general design process and design principle of harness.

Vehicle circuit design:

（1） Power distribution design Whether the design of vehicle power supply system is reasonable or not is directly related to the normal operation of vehicle electrical components and the safety of the whole vehicle. Therefore, the starting point of vehicle harness design in all countries in the world is mainly based on safety. The vehicle electrical system is mainly composed of three parts. Battery direct power supply system (usually referred to as ordinary power supply or 30 power supply). The load connected to the power supply is usually a safety component or an important part of the vehicle. The main purpose is to control the power of these components as little as possible to ensure that these components can work normally even if the car is not started. Go to the site for maintenance, etc. For example, the working power of engine ECU and engine sensor. This part of the electrical equipment is basically only used when the engine is running, and the power supply of the generator avoids the possibility of competing for power when charging the battery. For example:Instrument power supply，Ffc flexible flat cable, airbag power supply, etc. When the engine starts, the power supply of the load (usually referred to as ACC power supply) is removed. This part of the electrical equipment usually has a large load and does not have to work when the car is started. Generally, it is cigarette lighter power supply, air conditioner power supply, radio power supply, wiper power supply, etc.

（2） Line protection: The car harness is designed to protect the wires, and the protection of the electrical components of the circuit should be considered at the same time. The protection device mainly includes fuse, circuit breaker and fuse.