What could be the reasons for a car radar not alerting?

[VonJosiah]

There may be several reasons why a car radar does not alert: 1. Loose radar host wiring: If the reverse radar does not beep, first check whether the power cord of the host is properly connected and whether there is current; then check if the radar host wiring is loose. If neither of these is the issue, the problem may lie with the radar itself. 2. Damaged wiring at the bumper: When the reverse radar does not beep, you can also check whether the wiring connection at the bumper is intact, then check if the reverse light turns on when shifting into reverse gear. If it does not, check if the reverse light connection switch is damaged. You can also check if the computer displays any fault codes. If none of these issues are found, proceed to check whether the reverse radar itself is malfunctioning.