There is transistor switch on the controller that controls the power to the light. If that transistor is shorted, or is overloaded due to cable stress or misconnection, it can be affected. In the case of the 9FET RCS/CCS/OC controllers, it will fail while in the “on” position.
We recommend removing the battery and performing a connection inspection to reduce issues such as loose or dirty connection. After the inspection, you can test the part again to see if the issue persists. If the problem continues, contact our technical support team for additional assistance.