Disconnect the 3P connector from the motor.

Check battery voltage is measured between terminal 1 and terminal 3 at all time.

Check if the battery voltage is measured between terminal 2 and terminal 3 when ignition switch and audio switch is turned on.

Connect battery source to terminal 1 and terminal 2 of component side and check that motor operates (Antenna moves up).

Then, disconnect battery source from terminal 2 and check that motor operates (Antenna moves down).