Heater and a/c issue
My heater and a/c doesn't have much power. Fan speed is set or high and after driving 30+ min it starts to heat up but not on high. In warm weather the a/c just blows air. Not cold. Not on high when set on high. My knowledge is minimal. Could it be a fuse? Doesn't something needed replaced or simply recharged? Cheap? Expensive? Sitting at 99700 miles. Any help is greatly appreciated!