2003 Mitsubishi Lancer

The heat never comes on. I have left it on for hours while driving and it never gets hot or even luke warm.

I checked that. The engine is hot and one hose is cold and the other is hot. I had someone look at it and they said it was the heater core- that I need a new one. Do you know where I can find a heater core for my car? I have went to every website and no one has a heater core for sale.

Hey I might be able to help! I have the same car and my heater was acting up a bit but it was with the dials on the dash. When I looked up underneath the dash and took out the dash I found that a plastic piece was broken that turns all the other little wheels to push the lever that makes the air hot and cold. Try looking under your dash, in the direction of the a/c and heat control. You should see a thin metal rod. It should look like a silver hangar rod. Follow the rod to a white plastic box lookin thing and try to move the part that the wire is connected to. It should look like little gears, or a pear shaped gear. It may take some umf to move it but this way you'll know it's nothing mechanical from the box up. Just watch your fingers and make sure you don't pinch them in the little gears. I hope this helps! Good luck!