Hello, i have problem with my dual mc33926 controller. When i load test program(https://github.com/pololu/dual-mc33926-motor-shield/blob/master/examples/Demo/Demo.ino) on Arduino Uno output M1 works normally, but in M2 works only led indication. Multimeter shows what no voltage on between M2A and M2B and short circuit. Two gearmotors (488:1 Metal Gearmotor 20Dx46L mm 12V CB (https://www.pololu.com/product/3485)) works correctly on M1 outputs and from power supply (AA Battery 1.5v x12). Where i can watch trouble in this situation?
I am sorry that you are having trouble using your MC33926 shield. Can you verify that you get the same behavior when you swap your motors? How are you supplying motor power? Can you post pictures that clearly show your motor output connections as well as any soldered joints on the shield? It would also help if you shared pictures or a link to a video that shows how you are measuring the voltage at the M2 outputs.
When the engine swap the result does not change. Photo and video can only be done in 8-10 hours.