What are the functions of car connecting cables? Let’s take a look together.

In modern automobiles, electronic control systems are closely related to automobile wiring harnesses. It can be said that the microcomputer is equivalent to the human brain, the sensor is equivalent to the sensory organ, the actuator is equivalent to the motor tube, and the wiring harness is the nerves and blood vessels.

From a functional point of view, automobile connection harnesses are divided into two types: power lines that carry the power of the actuator and signal lines that transmit sensor input instructions. Power wires are thick wires that carry large currents, while signal wires are thin wires that do not carry power (fiber optic network communications).

The cross-sectional areas of wires used in motors and actuators are 0.85 and 1.25 mm2. The cross-sectional areas of wires used in power circuits are 2, 3, and 5 mm2; and in special circuits (starters, alternators, engine ground wires, etc.), there are 8, 10, 15, 20mm2 different specifications. In addition to electrical system performance considerations, wire selection is also limited by the physical capabilities of the vehicle. For example, doors and body wiring in taxis that are frequently opened/closed should be made of wires with good flexibility. In recent years, the number of electromagnetic shielded wires used in weak signal circuits has also been increasing.

How to explain the characteristics and rules of automobile connecting lines? Let’s take a look together.

The car connection line is generally composed of a single wire, with the electrical equipment connected in parallel, the negative pole grounded, and divided into multiple main lines centered on the ignition switch. So let’s learn about the characteristics and rules of car connecting cables!

1. Battery positive wire: The car cable can be led directly from the battery fuse box, or directly from the battery positive wire to the starting end. At the starting end, the thin positive wire is led to other circuits.

2. Ignition, instrument, and light wires: The circuit needs to be connected through the car key.

3. Dedicated line: No matter how the engine works, there are electrical equipment that need to be contacted, such as the cigarette lighter of the tape recorder, etc. , should be equipped with a single ignition switch for power supply.

4. Start control line: The car connection line makes the control switch (touch panel) of the main circuit action often connected and disconnected through the magnetic switch. There are three types of wiring methods. The attraction coil of the magnet switch of the small-power starter keeps the coil from the ignition The starting range of the switch is controlled, and the attraction and holding coil of the high-power starter is controlled by the starter relay (Dongfeng Jiefang and Mitsubishi heavy-duty vehicles, etc.); in cars equipped with automatic transmissions, in order to ensure neutral starting, the starting control line is often Connect in series with neutral switch.

5. Turnout:

The joints of automobile connecting wires are distributed throughout the entire body and are connected with different metals such as iron, copper, aluminum, aluminum, iron, etc., forming an electrode potential difference. Some joints are easily contaminated by mud, water, oil, rust, etc. Some nodes are thin metal sheets, and the indicator lights may cause the instrument not to work, the horn not to sound, etc. The nodes are not good.