unplug blower motor. run positive and ground jumpers direct from battery to check in blower motor works. The ground or negative is the lower blade. If blower runs, it is more than likely the blower motor speed resistor just rear of the passenger side of engine. Take it out and re-solder all 5 plug contacts on board. Try it. Most times this will fix it , as the part makers cheap out on solder and thats why they fail.