Attention! Troubleshooting in electrical equipment should always begin with a detailed study of the electrical circuits of the connections of assemblies and components.
The causes of failures in electrical equipment are often - poor contact in the alarm loop or switch, corrosion of connections, blown fuse or fusible link, defective relay or damage to the wire insulation and short circuit. For troubleshooting, you must always have a set of wires with clamps of various types (forks, pins, «crocodiles» and so on.), combination tester or tester, a 12 V test lamp can help out. The workshop always has a set of universal cable connectors (UKS), installed in the breaks of the AL of the car network and allowing measurements and switching. To check the presence of voltage in case of a malfunction of the unit or unit. In this case, it is necessary to determine the presence of voltage between the battery and the consumer «half» method. The essence of this method is that the presence of voltage or its disappearance is detected in the middle of the area under study, gradually cutting off the tested areas until the appearance or loss of voltage is detected. One of the main causes of failures is weak and unreliable contact.
The search for a short circuit is carried out by installing a probe. A probe or tester is installed in place of the blown fuse (ammeter). Shake the wiring harness, if the lamp starts flashing or the arrow deviates, then this wiring harness has a short to «mass». The main reason for this is the violation of the insulation of the wire and its contact with the car body. It remains to determine only the specific wire in contact with «weight».
To check the serviceability of grounding, use a test lamp with an independent power source. To carry out the test, it is necessary to turn off the battery by removing it «–» terminal. Now securely connect one end of the probe to the body, and the other to the terminal or harness being tested, if the probe lamp is on, then the contact is reliable, and vice versa.
A circuit integrity check is carried out to detect breaks in the power circuit of a particular node or device. To confirm the suspicion of the integrity of the circuit, it is replaced with a temporary, known to be good, conductor.
Another way to check the continuity of the circuit is to connect an ohmmeter. To do this, you need to remove the voltage - turn off «–» AB terminal, disconnect the circuit section from the power source and its consumption device. Connect tester (ohmmeter) to the ends of the section. With the integrity of the circuit, its resistance is close to zero, with an open circuit, the device shows infinity.
Breaks should be localized by placing new conductors along standard bundles using existing clamps and lugs. If necessary, additional fastening of the wire being laid, you can use insulating tape. At the same time, it should be ensured that the distance between the pipelines of the brake actuator and the wires to be laid is at least 10 mm. If the wires vibrate together with the motor or other components, then this distance should be at least 25 mm.