I thought that would have it sussed, but when I hooked the cable back up to the motor it arced pretty good. So maybe the cable was symptomatic of the real problem and the stepper motor had burned out. But since my original plan was to try a different motor it was no problem to swap it out.
After fixing the cable and swapping the motor out everything seems to be back in working order. I don't want to curse things, but I feel like I'm getting pretty good at this 3D printer maintenance thing.