Attention! Troubleshooting electrical equipment should always begin with a detailed study of the electrical circuits of the connections of units and components.
The most common causes of electrical equipment failures are poor contact in the AL or switch, corrosion of connections, blown fuse or fusible link, relay defect or damage to wire insulation and short circuit. To troubleshoot, you should always have a set of wires with clamps of various types (plugs, pins, alligator clips, etc.), a combined tester or probe, a 12 V test lamp can help out. Service stations always have a set of universal cable connectors (UCC) installed in the breaks of the AL of the vehicle network and allowing for measurements and switching. Check for voltage in case of malfunction of a unit or assembly. In this case, it is necessary to determine the presence of voltage between the AB and the consumer using the "half" method. The essence of this method is that the presence of voltage or its disappearance is detected in the middle of the examined section, gradually cutting off the checked sections until the appearance or disappearance of voltage is detected. One of the main reasons for failures is weak and unreliable contact.
Search for a short circuit by installing a tester. A tester or a tester (ammeter) is installed in place of the blown fuse. Shake the wiring harness, if the lamp starts to blink or the arrow deflects, it means that there is a short circuit to "ground" in this wiring harness. The main reason for which is a violation of the wire insulation and its contact with the car body. It remains only to determine the specific wire in contact with "ground".
Check the serviceability of the grounding with a test lamp with an independent power source. To perform the check, it is necessary to disconnect the battery by removing its "-" terminal. Now securely connect one end of the tester to the body, and the other to the terminal or harness being checked, if the test lamp lights up, then the contact is reliable, and vice versa.
The integrity check of the circuit is carried out to detect breaks in the power supply circuit of a particular unit or device. To confirm the suspicion of the integrity of the circuit, it is replaced with a temporary, obviously serviceable, conductor.
Another way to check the integrity of the circuit is to connect an ohmmeter. To do this, remove the voltage - disconnect the "-" terminal of the battery, disconnect the section of the circuit from the power source and the device consuming it. Connect the tester (ohmmeter) to the ends of the section. If the circuit is intact, its resistance is close to zero; if there is a break in the circuit, the device shows infinity.
Localization of breaks is carried out by installing new conductors along standard bundles using existing clamps and tips. If additional fastening of the laid wire is necessary, insulating tape can be used. In this case, it is necessary to ensure that the distance between the brake drive pipes and the laid wires is not less than 10 mm. If the wires vibrate together with the engine or other units, then this distance should be at least 25 mm.