How to Check for Positive Short Circuit in Car Electrical Circuits?
2 Answers
The car's electrical circuit has many branches, each with its own fuse. A short circuit will cause a positive to ground (negative) connection, which can often be observed with the naked eye. To check with a multimeter, measure the resistance between the top end and the fuse. Insert one end of the test light into the battery's positive terminal and the other end between the top end and the fuse. In the circuit, if the current does not flow through the electrical appliance but directly connects the two poles of the power supply, it is called a short circuit (Short-circuit).
I've been driving for many years and have experience in troubleshooting positive circuit shorts. First and foremost, safety is the top priority: after parking, turn off the engine and immediately disconnect the battery's negative terminal to avoid electric shock or fire. Then, take out a multimeter and set it to resistance measurement mode. Clip one probe to the car body as the ground and use the other probe to test suspicious circuit points. If the reading is close to zero or the meter beeps, it indicates a short circuit there. I focus on checking areas prone to wear like the engine compartment and door frame wiring harnesses because high temperatures and vibrations can cause insulation to break and touch the positive terminal. Also, check if the fuse is blown; if it is, lock onto that circuit and perform segment testing. Preventive measures are practical too: regularly inspect wires for aging, especially in older cars—don't overlook this. After finding and repairing the short circuit, test the charging system voltage to ensure it's not too high, which could blow the fuse. DIY is simple and efficient, but don't push through with complex situations—it's safer to seek professional help.
