My heater blower is not working all speeds. High speed went out first.

Sounds like the blower motor is gone. have it tested by a shop or someone with electrical backround.

the resistor fails allowing the blower motor to draw excess amperage, in return melting the wires to the blower motor resistor. part number for resistor 1-05061575aa, part muber to the repair harness is 1-05017124ac