Hi,
An automotive lamp will do, 5W to 20W or so, doesn't need to be a headlight.
An LED would be to light a load for the controller, considering we are troubleshooting about driving a decent load.
OPs Motor Plate
Hill House Products do have a web site, might be worth giving them a ring.
Those motors for tennis and baseball launchers can be very current hungry, especially on start up.
Have you measured the battery voltage while connecting the motor directly to the battery.
Tom.. 