Check fuse if the blower is not working. If it is then replace your heater core. if its not then replace your fan switch.
AnswerBad thermostat, clogged heater core, or a defective heater control switch. If an engine has not been running long it will not have warmed up, the warmth from a car heater usually comes from the engine.
heater fan blower motor is burn up not working need to replace it could also be a heater relay typically located on the fuse panel that needs replacing could also be the switch on the switch panel
Low coolant? Defective thermostat? Heater core "airbound"? Water pump circulating coolant? Selector switch working? Temperature control cable?
Fuse- Blower Motor- Wiring- Selector switch fail- i8f you still have heat to the heater core, if the heater core is cold, and the mottr is still hot... change the thermostat
Not knowing what year, make and model you have, I would suspect the heater fan switch and or electrical plug to the switch is at fault.
blower motor bad or no power to it chech fuses blower switch blower motor
A restricted/plugged heater core can do that. Try flushing the heater core.
It is either the fuse or relay. also check the heater/ ac control switch.
The blower motor speed switch is burned out or the fuse is blown.
there seems to be a short in the electrical system, i would start by checking the heater switch,
It sounds as if you have a defective ignition switch. The next time it happens you need to turn the key slightly. If it starts working then the ignition switch is bad.