My Powerchair joystick controller lights ripple up and down a few times then shuts off.

This means the joystick controller has been locked to prevent unauthorized use. The joystick may have been inadvertently set in the lock mode. The locking and unlocking method is achieved through a sequence of key presses and joystick movements. Consult your Powerchair User Manual for more information on locking and unlocking the joystick controller.