the blower motor resistor is broken, get a replacement.
The blower motor speed resister is burned out.
If the blower works on slower speeds only I would suspect the high speed blower motor relay (under the hood in the power distribution box) or the switch itself. The blower speed resistor is working if all the slower speeds work.
Normally when some speeds work and others don't, the problem is a bad, Blower Motor Resistor Pack. You will find it somewhere near the blower motor.
If all speeds do not work, suspect the fuse, the switch, the switch connector or the blower motor. If only high speed works, suspect the blower motor speed resistor. If low speeds work and not high, suspect the blower motor relay.
change the blower motor resistor . this controls the speeds . thanks paul
Probably the blower motor speed resistor is partially burned out.
If you only have high speed I would blame the blower speed resister. If you have no speeds and the fuse is good, I would blame the blower motor or the switch.
If the HVAC blower motor does not work on any speeds, I would suspect the motor or the switch is bad.
Blower Motor Resistor Pack is defective.
On most cars there is a high speed relay that can go bad and would need replaced .
the reason blower does not work on all speeds, is the fan blower motor resistor. The resistor is a 4-5 step series circuit, 1 resistor is added for each reduction in speed. If one burns out then so will all speeds below it. The "high" circuit usually has a separate fuse and bypasses the resistor altogether.
usually the blower motor resistor pkg. located on or near the blower motor