Check that the battery output of theis normal. If the output is too low to prove that the battery is out of order, it is urgent to replace the battery.
Check the switch. A positive pole and signal line with a short wire switch which, if the car can turn, proves that the turnstile is broken and is in urgent need of replacement or repair.
Whether the controller is good or bad. You can use the positive 5 V short connection of the turnstile, such as the rotation of the switch to indicate that the controller is no problem.
Check motor quality. Motor carbon brush contact is not real, will also cause electric bike without electricity.
The power indicator on the dashboard is not on and the motor is running normally.
No voltage between positive and negative lead of dial: poor contact of connector or broken lead: reconnect or change wire;
Damage of luminous tube: replacement or repair of luminous tube;
Open circuit on dial board: replace or repair instrument circuit board.