The outputs of a stepper motor driver like this must either be completely open (in which casenothing happens), or connected to an inductive load like a motor winding. Using a resistive load
Method of shunting is an excellent idea. I tried it over the weekend using a 0.1 Ohm 2W resistor. But I didn't get any reading in my multimeter(in Ammeter mode).
Following this topic I just got an idea and tested it on my stepper, a NEMA 17.
Oops, Nano... I use UNOs and Protooner boards.