So far I've checked the fuse, the switch and the rear plug. The fuse is fine as the switch illuminates when I press it. I'm not getting any power at the connector plug to the fan motor, although I'm not certain that is because there isn't power coming from the switch. The defroster fan motor has what appears to be an external resistor and possibly also a circuit breaker attached to the outside of the fan housing. Again, electrical isn't my strong point, so is there a way to test both the resistor and circuit breaker to see if they're working? My assumption at this point is that since they're there, they must ultimately provide power to the fan which may be why I'm not getting power at the plug. My wiring is fully wrapped and fine as far as I can trace it, as this car was in nearly new condition when I bought it a few years ago with all wiring unhacked.
Right now my assumption, until proven otherwise, is that I have either a bad resistor, circuit breaker, fan, or a combination of any of the three.