Disconnect the limit switch and operate the limit switch.

Check for continuity between the terminals.

If there is an abnormality, replace the limit switch.

Check that the motor stop after about 1/2 turns counterclockwise.

Check that the motor stop after about 1/2 turns clockwise.

If operation is not as specified, replace the motor.

Disconnect the connectors for each motor.

With the battery connected directly to the motor terminals, check if the motors run smoothly.

Reverse the connections and check that the motor turns in reverse.

If there is an abnormality, replace the motors.