Talking about the common problems of using a digital multimeter to measure car circuits: As long as the buzzer sounds, it is considered that the wiring harness is good
The core of this question is when will the beep sound. After testing, it is found that when the multimeter measures a 68 ohm resistance, the buzzer will also sound, and the wiring harness must be damaged. Most cars use 12V voltage. Take a 1-ohm motor as an example. Calculate through Ohm’s law, I = U/R = 12/1, and the working current is 12A. If a 1-ohm resistor is added, the current will drop to 6A. So put a 68 ohm resistor in series and the device won't work.
