the switch to turn on heat is not working at times on my 2009 hyundai elantra, is it a fuse? a mechanic told me there is a box in the dashboard that could need to be replaced and it could cost almost $300.00 for that alone not including labor?

Thank you for the advice.

I have a question about my 2009 hyundai elantra heating issues. at first the switch wouldnt turn on until i started driving the car and it blew out cold air. They changed the fan relay (?) switch. After that the switched turn on when i started the car. However, after warming the car up for 45 mins its only slightly warm? They now changed the gasket, blower motor resister & the thermostat. And they also did a heater core flush. As of now, when I start the car the air is cool, after driving the car for a while the heat will work well, but when i stop at a traffic light cool air comes out? And then when I hit the gas again to drive the heat comes back on. Can it be the blend door actuator?