What are the common methods for checking circuits?

[SkylarLynn]

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.

[ZaneFitz]

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.

[MaddoxDella]

When encountering circuit issues, I first use a multimeter to measure key point voltages and compare them with the manual's standard values. Next, I check connector contacts—many faults are caused by loose or oxidized interfaces. Pay special attention to the fuse box: locate the corresponding position as per the manual, pull out the fuse, and inspect it against light. Measuring ground resistance after disconnecting the battery is crucial; sanding rusty grounding points on the chassis shows immediate results. A circuit tester pen is super handy for tracing wires—the section where the light doesn’t illuminate is definitely problematic. If possible, using a diagnostic tool to read fault codes is more accurate, but basic tools suffice for troubleshooting most issues. Always wear insulated gloves when working.

[Julian]

I have a set of practical tips for circuit testing. Using a multimeter to check continuity is the most basic method, and using the buzzer mode to listen for sound is faster than reading the display. The segmentation method works particularly well: first test from the power source to the switch, then from the switch to the load. Unplug all connectors and scrape the contacts—oxidation layers often cause issues. Fuses can be checked visually; a blown fuse will appear black. Temporarily connect a 12V test light to suspicious circuits—if the light turns on, the circuit is complete. You can also judge by listening for the relay's clicking sound. Remember to disconnect the battery throughout the process; last time, a short circuit gave me quite a scare.