1, fuse on battery box burn out, replace fuse.
2, the battery box of electric bicycles fuse contact is bad, adjust fuse tube, make it contact well.
The contact on the battery box is not in good contact, adjust the contact so that it is in good contact.
4, battery box contact burn out, replace new contact.
5, the electric door lock burns out, the replacement new electric door lock.
The battery lead in the battery box is broken and the connection line is updated.
7, battery inside the battery box broken, replace or repair the battery.
8, electrical door lock lead or contact lead broken or bad contact, rewiring.
3, how to detect brushless motor?
Unplug all motor and wire harness, use multimeter diode file, point multimeter red needle on motor six-core plug thin red wire, black needle on thin yellow, blue, green and black wire, numerical value is more than 900, point red needle on black line, Black needle refers to the fine yellow, blue, green and red line, the value is 500-600.
Under the condition of electrification, using the 200V DC voltage of the multimeter, the black needle refers to the thin black line of the six-core plug, the red needle refers to the thin yellow, blue and green lines, the motor rotates and the voltage shows the change between 0-6.25 volts.