The common faults of automobile circuit are broken circuit, short circuit, damage of electrical equipment and so on. In order to diagnose the fault quickly and accurately, several common inspection methods are introduced below.
1, visual diagnosis: fault car circuit, sometimes the abnormal phenomenon of smoke, sparks, noise, smell, fever etc.. These phenomena can be observed directly so that the location of the fault can be determined.
2, law breakers: ground fault circuit breaker device, determines available method, is suspected of a ground fault circuit section after disconnection, observe the electrical equipment grounding fault still exists, in order to determine the location and cause of the grounding circuit.
3, short circuit fault occurs: the automobile circuit, can also be judged by short circuit method, namely using the screwdriver or wires of the suspected circuit is an open circuit short circuit, observe the pointer changes or electrical equipment working conditions, so as to determine whether there is fault in the circuit breaker.
4, test lamp method: test lamp method is to use a car bulb as test lamp, check the circuit is no circuit fault.
5, the instrument method: To observe the Baotou North Benz parts on the dashboard of current meter, Baotou North Benz parts temperature gauge, fuel gauge, Baotou North Benz accessories such as oil pressure gauge indication, judging circuit has no fault. For example, the engine cold, turn the ignition switch, water temperature gauge indicates a full scale position does not move, indicating water temperature sensor failure or the ground line.
6, low ground fire test method: a thread that is removed by the electrical equipment metal part of the car touch and try to judge sparks. This method is simple, the method is often used in auto electrician, ground fire test method can be divided into direct and indirect ground ground two. The so-called direct bonding, is without load and direct bonding to produce a strong spark. For example, we have to determine the ignition coil to a battery circuit is faulty, ignition coil and detachable connected to the ignition switch head, scraping in the car body or frame, if there is a strong spark, the circuit is normal; if no spark is generated, the circuit breaker appeared. Indirect ground is through a load of automobile electric appliance and ground produce weak spark to judge whether there is fault or load line. For example, the conventional ignition system fault electrical cable grounding, if there is a spark, this section of the line is normal; if there is no spark, the circuit breaker. Of particular note is that the test method cannot be applied to electronic circuit vehicles.
7, high pressure test method of fire: high voltage circuit for ground fire test, observation of electric spark, to judge the work situation of the ignition system. The specific method is: take off the ignition coil or spark plug of high voltage wire, and align it with the spark plug or cylinder head, etc., the distance is about 5mm, and then switch on the starting switch, turn the engine, see its jumping fire situation. If the spark is strong, the sky is blue and the fire is loud, it shows that the ignition system is working normally; on the contrary, the ignition system is not working properly.