Troubleshooting a scooter is like any electric device. power starts from the battery terminals and it has to reach the motors in a controlled manner using a signal coming from the throttle that “talks” to the controller which sends the juice to the motors., so you unfortunately have to follow it logically from start to finish to see which component does not perform its task. So you need a meter that reads DC volts and trace the fault. Not so simple for everyone. Aside from making sure all your cables are plugged in securely, and nothing is shorted out, or a rubbed through wire it’s hard to give advice. Some displays show error codes as well, the dualtron is a quality scooter - any error code?