Take the white connector at the end of the red wires and plug it into the right-hand side of the FLEX controller. Repeat this process for the blue wires on the left-hand side.
Once you've plugged the wires into FLEX, double-check that they're all in the right place.
Connector and blue wires on the right-hand side of the FLEX Cap
Connector and blue wires on te left-hand side of the FLEX Cap
