Edit:

Just thought of this as well:
When you disconnect the fan connector and the two fan relays and measure the ceramic resistor to see if it is ok, also check the resistance of each side of the resistor to ground (it should be infinity/over range on your meter).
If you have any resistance to ground, then this will be drawing current while the fan hi circuit is operational, although your fan low would likely not be working properly.

Cheers