Why do the long row of top lights of police cars flash in front and not in the back?

There are several reasons why the long-row overhead lights of police cars flash in the front row but not in the back row:

1. Failure: The long row of overhead lights failed, resulting in the failure of the front flash. This requires maintenance or replacement of the long row of overhead lights.

2. Design: The design of the long row of top lights of police cars is different, and the front flashing and the back flashing are controlled by different circuits respectively. In this case, the front flash can work normally, but the rear flash can't.

3. Control switch: The control switch of the long-row ceiling lamp of the police car is set to the forward flashing mode. In this mode, the front flash can work normally, but the rear flash can't. Therefore, the reason why the long-row overhead lights of police cars flash in the front row and not in the back row is a problem of failure, design or control switch.