The front windows will not defrost. The fan is working and the heater works

Hello, if you have no defrosting or defogging, it is likely because the air conditioning compressor is not turning on as needed. When "defrost" is selected, the air conditioning compressor becomes active to dehumidify the interior of the vehicle and clear the windows. If the compressor is not turning on, the dehumidifying will not occur. Have testing performed focused in that area.