I have a 97 Subaru Forester that has an issue with the heater. Basically for the past year now I have been unable to use the heater when I turn the dial to heat there is no heat coming out. From time to time it would work and then the Aircon wouldn't work correctly. What could the issue be? Thanks

generally a bad control unit in that case, or a bad blend door inside the dash that goes from heat to cold. But, that old, I'd flush out the heater core first, it could be plugged

Thanks for the help Scotty, I did notice that when this was happening that the actual Dial itself was very hard to turn and at times I was not able to turn the dial fully so I am going to guess its the control unit :/