Check that you not only have power but you have a ground path. A 12V test light is all it takes to do that. Check the power wire at the pump for a hot while referenced to a known ground, and if you have power there, then check for power referenced to the pump's ground. An open ground can certainly be the issue.
If the power and ground check out, check for continuity through the pump using a multimeter.
It's entirely possible that it simply gave up the ghost. I wouldn't be surprised, and wouldn't hesitate to replace it. The basic model ShurFlo pump is not expensive...