Why I don't have heater?

Hello; issues with getting hot air from your climate control can be caused by several reasons. First, you need to find out if your engine is not getting to a hot enough temperature and if you have proper coolant flow through your heater core. If the coolant does not get to the proper temperature for the engine -- such as due to a stuck open thermostat, the engine never gets to "operating temperatures" beyond 200 degrees -- then you will generate insufficient heat inside the car. If the coolant does not flow hot into the heater core and hot out of the heater core, then you will not get hot air either. Second, you'll need to learn if your climate control system is functioning as designed inside the vehicle. If the temperature selection is not affecting the temperature as desired, and you have hot coolant going through the heater core, you could have a temperature blend door issue -- either a control, blend door actuator, or heater plenum concern. Testing hands on will reveal an answer by checking into at least these areas.

One doable diy suggestion is check engine coolant level - while engine is COLD.