I'd say yes, and resistance would usually be better than diodes, depending on how sensitive your load is to the waveform. You could also use it to get an indication of impending mechanical fault conditions, as the voltage will vary with load.
A Hall effect sensor near to one of the conductors might save the resistance of a shunt if you can find one sensitive enough. It will depend on the current being drawn. Amps is probably OK, milliamps probably not.