How do I fix the heater in my car ?

With engine @ operating temp touch both hoses under the hood going to the heater core ...if both are hot you have a problem on the inside of the car ....
I think this might have a manual control so when you push lever to cool and hot do yopu hear a flap moving ...?
Make sure the coolant level is full ....
could be a bad thermostate also
You can look under the dash and find the cable going to the heater flap and while someone moves it back and forth you can see if its working OK

bg
March 2006