Check your fuse boxes.
the heater fan resister,it is or should be on inside or on outside heater box.
Blown fuse Loss of freon Does compressor run? Does blower motor work?
it is the blower motor resistor. it works on high because on high it bypasses the switch
Usually the blower motor resister has gone bad.
blower motor resistor is burned out
A reverse cycle air conditioner work like normal air conditioners only in reverse, transferring heat into a house instead of outside of one. It is not an air conditioner at all, but a heater.
If you mean the blower only goes in the high mode check the blower resistor located in the plenum under the wiper module.
If you are referring to the blower motor speed, and only the highest setting works, then the problem is a bad Blower Motor Resistor Pack.
Blower resistor needs replacementRelay for low speeds needs replacementBlow motor needs replacement (one of the 2 windings burned out)
Blown fuse? Bad relay? Bad switch? Bad fan motor?
Possibly. A bad blower motor resistor would cause the blower motor to either not function or function only on one speed (usually high speed). The air conditioning system is probably set up such that if the blower isn't functioning at all, the air conditioner won't function. Otherwise the air conditioner would overheat.