Heater and Defroster

is it the fan that stopped ?
check fuses ,resister and blower motor
let me know

no the fan still works it blows cool air

OK then you have to do this test to determine what is going on
does the engine reach operating temp if not ,check coolant and replace thermostat ,if so
you need to test the heater hoses
with engine running and at operating temp heater fan motor on high open hood and check heater hoses by the firewall

if both hot you have a blend door issue
if one warm or hot and other not heater core need to be flushed
isolate heater core and flush
let me know