Make sure the battery is charged and the fuse is intact. Check the blower motor and resistor assembly connections. Check the fuse, connections, and battery. Connect a voltmeter to the blower motor connector and test the blower switch. If there is voltage but the blower motor isn't functioning or the readings are high, the motor may be faulty. Disconnect the blower motor resistor's connector, connect a jumper wire and an ammeter, and test the blower switch. If readings are high, the blower motor is likely faulty. If readings are off in one or two switch positions, the resistor assembly may be faulty.