How to swap the motor wire on your 2020+ Surface 604Updated 3 years ago

1. Remove battery. Hold down the power button on the display pad for 5 seconds to drain remaining current from the system.

2. Remove the controller and disconnect the motor wire. 

3. Flip the bike over on it’s handlebar and saddle -make sure to protect the display. Clip all the zap straps securing the motor wire to the frame. 

4. Remove the front light and wiring harness (display/brake cut offs bulk wire) through the upper porthole in the down tube. It will make removing and replacing the motor wire easier with fewer wires in the way.

5. Cut the lower plug end off the damaged motor wire (the end that plugs into the motor). Electric tape a strong string to the cut end (e.g. a long strip of plastic box strapping). It needs to be long enough to pull the replacement back through the downtube. 

6. The hard part is pulling the motor wire through the controller compartment. Try using an 18mm wrench to push on the wire inside the compartment, while pulling on the wire. It eases off the friction pulling the wire around the U port. 

7. Electric tape the replacement wire end to the string. It will be the end with wire ends sticking out. Pull the string through the controller compartment. Pushing on the wire on the lower end at the same time will help. You might need to push down on the plug end through the porthole. To get into the controller compartment. Once in can pull it the rest of the way with the string.