How to Test the Quality of a Three-Wire Reversing Radar?
3 Answers
The three wires are divided into positive, negative, and one video line. Use a test light to measure the positive and negative poles, and use a multimeter to test the conductivity of the video line. After engaging reverse gear, lightly touch the surface of the radar probe; if there is vibration, it is functioning properly, while no response indicates a fault. More details are as follows: 1. Definition: The reversing radar, also known as the "reverse collision avoidance radar" or "parking assist device," mainly consists of ultrasonic sensors, a controller, and a display. 2. Components: Ultrasonic Sensor: Its primary function is to emit and receive ultrasonic signals, then input the signals into the main unit for display on the display device; Controller: Processes the signals to calculate the distance and orientation between the vehicle and obstacles; Display or Buzzer: When the sensor detects that the distance between the car and an obstacle reaches a dangerous range, the system alerts the driver through the display and buzzer.
I think you really have to try out a parking radar to know if it's good or bad. Like the three-wire radar on my car, after using it for several years, the testing method is actually quite straightforward: first check if the wiring is damaged or rusty, as wire aging is a common issue. Take out a multimeter, connect the red probe to the positive red wire to measure voltage—it should normally be around 12V; use the black probe to test the negative black wire for grounding, ensuring it's unobstructed. Then, shift into reverse gear, have a friend stand behind the car and slowly approach the radar sensor, while I measure the voltage changes on the middle signal wire with the multimeter. Under normal conditions, the voltage should fluctuate. If the voltage remains static or jumps erratically, the radar is likely faulty. I remember once when the sensor was scratched by tree bark, I misjudged the distance and almost hit a corner, so it's important to regularly clean dust off the sensor surface—it also helps extend its lifespan.
I love tinkering with car equipment in my spare time, and testing a three-wire reverse radar is super simple and fun! Just prepare a multimeter and a wrench: First, open the wiring box of the rear radar and check if the red, black, and green wires are securely connected. Then, start the engine and shift into reverse gear. Use the red probe to measure the voltage of the red wire—it should stay around 12V. Next, use the black probe to check the grounding of the black wire, which should read close to zero volts. The key is the signal wire—simulate an obstacle approaching the sensor, like slowly moving a foam board closer, and observe the multimeter display: A good radar will cause the voltage to fluctuate up and down. If there’s no response or erratic jumps, the sensor might be faulty and need replacement. Remember to test the waterproofing by spraying water after installing the radar—don’t let it fail in rain or snow during outdoor driving.
