Although we only produce automobile wiring harnesses, we will encounter customers who will ask questions about automobile wiring harness failures. After all, with the popularity of automobiles, more people will encounter such problems. Next, I will explain the causes and detection methods of the failure of the automobile wiring harness.
First of all, let’s take a look at the composition of automotive wiring harnesses, including wires, terminals, sheaths, tapes, PVC tubes, corrugated tubes, waterproof heat-shrinkable tubes, and some auxiliary materials, such as packaging, protective materials, etc., which are connections in the circuit Wiring parts of various electrical equipment. In order to facilitate installation and later maintenance, the wires of different specifications and colors used in the various electrical equipment of the vehicle are generally arranged in a reasonable bundle, and the wires are bundled with insulating materials. This is the origin of what we call the wire harness.
Common automotive wiring harness faults include poor contact of connectors, short circuits, short circuits, grounding, etc. between wires. These common failure causes are divided into two types: natural factors and human factors.
The automobile wiring harness has exceeded the service life, the wires are aging, and the insulation layer is damaged, causing short circuits, open circuits, and grounding between the circuits, thereby burning the wiring harness. In most cases, the failure of electrical equipment to work normally is caused by poor contact, and a large part of the reason is that the wiring harness terminal is oxidized and deformed.
When assembling or overhauling auto parts later, metal objects will scratch the wiring harness and break the insulation; the wiring harness is incorrectly positioned, and the remaining space is too large or too small; the lead position of the electrical equipment is connected incorrectly; the positive and negative terminals of the battery are reversed; When there is a problematic circuit, connect or cut the wires randomly. These factors will affect the electrical equipment and even burn out the wiring harness.
Cars sometimes have various problems, how do we judge which link is wrong? To solve the problem, we must find specific short-circuit points, and we need to check the entire electronic system circuit, but this is cumbersome and workload Big thing. The automotive electronic system supports many functions, and the wiring harness of the system is more complicated. The wiring harness of the whole vehicle is composed of a trunk road and a number of branches. There are dozens of sensors, electrical appliances, and switching elements on it. It is very difficult to find a short-circuited point from such a complex and huge system.
So since it is so complicated and time-consuming to check the car circuit fault, is there no easy and fast way? Electrical appliances in automobiles generally use car sound grounding, which means that the circuit flows from the positive electrode of the battery to the electrical appliance, and then flows back to the negative electrode of the battery or flows back to the negative electrode of the battery through the body as a loop. Once a short circuit occurs, the current will not flow through the electrical appliances and directly flow back to the negative electrode of the body to form a short circuit. In order to avoid the large loss caused by the short circuit fault of the wire harness line, most fire lines will set the fuse, the function is to cut off the line in the short circuit of the wire harness line. When the car harness is short-circuited, we generally use a test light to connect to the positive electrode of the battery. If there is a fault, the test light will be lit. But at this time, we can't observe the current flow inside the wire harness. The current sensor clamp is a good sensing tool.
The above information is provided by the wiring harness supplier.