Heater issues in the fall

I have an 03 Mistubishi Galant with a heater than is not working. The fan works and I changed the thermostat on the engine, but I still have no hot air blowing through the vents in the cab of the car. I don’t feel the supply or return hoses to the heater core are hot after running the car for a while either. Anybody have any ideas?

Did it work last year? I don’t know what system you car uses, but most cars use one of three systems.

Mechanical controls: You push a lever and that opens the blend door (The blend door blends heated, inside or outside, or cool air) or valve to allow heat in.

Vacuum controls: You push a button or turn a knob and that opens or closes a valve that uses vacuum to move the blend door

Electronic (this one I will try to continue to avoid until they get it right): It uses electric motors to control heat and air.

Likely one of those systems have failed. Since they work in different ways, it is hard to suggest how to trouble shoot on when I don’t know what your car uses. Hopefully someone else here will have some good useful suggestions.

Thanks yeah it did work last year very well, I took off the climate control panel and also the front panel under the drivers side and it looks to be a mechanical system. As I turn the heater knob to heat the dial pulls a cable thus opening or closing the damper to the heating core. But I couldn’t actually get to any of it without taking off the dashboard.

If the supply and return lines to the heater core are not hot, there is a problem. Once the engine is warm they should be hot. That’s the first thing. Is there hot engine coolant flowing through the heater core? If not, figure out why it’s not flowing.

The heater core must be hot before anything else is considered, and, unless I misinterpreted your post, you said it wasn’t hot.

Could your car, perhaps, need a new thermostat? Is the engine reaching normal operating temperature quickly? Have you noticed any decrease in fuel mileage lately?

Make sure your car has coolant.