Why does the reversing radar not beep on rainy days?
3 Answers
If the problem is confirmed to be with the reversing radar, the first possibility to consider is a faulty buzzer. In this case, you need to purchase a new buzzer and install it. Additionally, recall whether your car has undergone any recent modifications. If so, it is possible that the wiring of the reversing radar was damaged during the modification process. This would require taking the car to the original repair shop or a 4S store for inspection. There are many other methods as well. Pay attention to the installation height: When installing, the owner must pay attention to the installation height: generally, the front installation should be 45~55 cm from the ground, and the rear installation should be 50~65 cm. Clean the probe: To ensure driving safety, the owner should regularly clean the probe to prevent dust accumulation. Precautions: Do not cover the probe surface with hard objects, as this may cause false alarms or inaccurate distance measurement, such as when mud covers the probe surface.
I've encountered this issue several times. On rainy days, the reversing radar seems to be asleep. The main reason is that rainwater covers the sensors on the rear bumper, and the ultrasonic waves get interfered with by the water. Last year, I specifically consulted a mechanic. He said the sensors are like human eyes being covered—the more rain, the stronger the interference. He recommended wiping the sensors with a tissue before driving in the rain, especially the recessed square ones that tend to collect water. Also, for older cars, pay attention to the aging sealant on the wiring harness connectors; rainwater seeping in can cause a short circuit. The safest bet is still to rely on your own judgment by checking the rearview mirror. During heavy rain, I usually roll down the window to listen for sounds.
Last time during heavy rain, I almost hit a fire hydrant while reversing, and the radar didn't make a sound. After understanding the principle, I realized: each radar sensor emits ultrasonic waves, and high raindrop density can interfere with signal transmission. Especially for aftermarket radars, misaligned sensors are more prone to being covered by rainwater. My current habit is to ask the car wash attendant to focus on rinsing the sensor areas and then use an air gun to dry them. A temporary solution is to turn off the air conditioning defrost while reversing to reduce window condensation. I remember one winter with sleet, ice covering the sensors caused the same issue – I had to pour warm water to restore them.
