What Are the Techniques for Diagnosing Automotive Circuit Faults?

[Brian]

Basic diagnostic methods for automotive circuit system faults: 1. Visual Inspection Method: When a circuit fault occurs in a car, abnormal phenomena such as smoke, sparks, unusual noises, burnt smells, or overheating may appear. 2. Open-Circuit Method: If a short circuit (ground fault) occurs in automotive circuit equipment, the open-circuit method can be used for diagnosis. This involves disconnecting the suspected faulty circuit segment and observing whether the ground fault persists in the electrical equipment to determine the location and cause of the circuit fault. 3. Short-Circuit Method: For open-circuit faults in automotive circuits, the short-circuit method can also be applied. This involves using a screwdriver or wire to short-circuit the suspected faulty circuit and observing changes in the instrument pointer or the operational status of the electrical equipment to determine if an open-circuit fault exists. 4. Test Light Method: The test light method uses an automotive bulb as a test light to check for open-circuit faults in the circuit. 5. Instrument Method: Observing the readings on the car's dashboard instruments, such as the ammeter, water temperature gauge, fuel gauge, and oil pressure gauge, can help identify circuit faults. 6. Low-Voltage Ground Spark Test: This involves removing a wire from an electrical device and touching it to the car's metal part (ground) to check for sparks and diagnose the fault. 7. High-Voltage Spark Test: Performing a ground spark test on the high-voltage circuit and observing the spark condition can help assess the performance of the ignition system.