What are the common methods for checking circuits?
2 Answers
Methods for checking circuits include: 1. Visual Inspection: Determining the fault range by observing surface phenomena such as car gauges, indicator lights, and circuit connections; 2. Spark Test: During driving or in the absence of instruments, grounding a wire or terminal to the car body or touching a wire to a terminal to observe spark generation, thereby assessing current supply and flow; 3. Testing Method: Using instruments to test circuits or components to identify faults; 4. Replacement Method: Replacing components or wires to determine faults; 5. Spark Plug Test: When it is confirmed or suspected that a certain engine cylinder is malfunctioning, the spark plug test can be used. This involves disconnecting the high-voltage wire from the spark plug of the cylinder while the engine is running, creating a 5mm to 7mm gap between the wire and the spark plug, and performing the test. If the engine performance significantly improves, it indicates the spark plug is faulty. If there is no improvement, the spark plug should be replaced.
The most common method I use to check circuits involves three steps. First, inspect the appearance—unplug the connector to check for rust, deformation, or damaged wire insulation, which can be spotted directly. Second, use a multimeter to measure voltage and continuity by placing the probes at both ends of the circuit to identify breaks or excessive resistance. Third, perform a substitution test—borrow a known-good part from a friend's car, like a bulb or relay, and swap it in to see if it works. Another trick is using a short-circuit test light; if the light turns on when connected, it confirms power is reaching that point. Always remember to disconnect the negative battery terminal before working on the car—I once forgot and nearly got shocked. Safety first! Keep a set of tools in your car so you can troubleshoot anytime issues arise.
