By "third position", do you mean the "HI" position? First of all, your charging voltage is TOO high! You'll be "boiling" the battery in no time flat. I would start with changing the voltage regulator. I would (and DID) replace the regulator with a Wells VR715 solid state model. It fits in the original footprint and plugs right in! AND, the cost is around 10 bucks. Just be sure that the mounting ears are grounded to the radiator support for proper operation. NOW, the blower switch getting hot COULD be caused by an arcing condition between the wire harness plug and the switch connectors. If you can, unplug the connector from the switch and check the spade connectors for any signs of burning...the plastic connector might be slightly "deformed" if the connections were overheating. First, correct your overcharging problem, and then take a look at the heater switch connections.