A month or so ago the heater in my wifes 97 D-90 stopped working, it worked fine until then (except the low didn't really blow). I stuck my hand in the fan and found a rag caught in the fan.
1. I removed the rag and ran the power directly to the fan motor, the motor started, no problem at all.
2. I checked the fuses that are located in front of the differential shifter and under the hood, all checked out.
3. I ran a ground wire from the wires that plug into the switch to see if the switch wasn't working, nothing happened, no power at the fan power wire.
My question is, what else could I test to locate the problem??? Could it be a relay or something like that??