07 1500 lt z71 heater motor issue
 

so I go into work to do my weigh-in for my physical readiness test and my heater motor is working so far as I can remember. I get in my truck to actually go in and the motor isn't running on any setting. so I do the logical thing by checking fuses, and the ones I found or could figure were for the heating system were good. it has the dual zone driver/passenger comfort system, which the passenger rarely gets used, with auto temp control which never gets used.

so what I am trying to figure out is if it's the resistor module or the fan. from what I can tell from what I have found on the web, if it was the resistor module, it would work on full blast. but it doesn't blow on any setting, all the way down or all the way up, or even vent zone. what is the guru's opinion?