if this step is no issue, start engine, turn the hot air button on, measure the wires voltage; if it's not between 12-14vdc, the control is a failure.
climate control involve with electronic board, that's a hard part. there are also some contact-points, if you are lucky, you can clean up those touch-points with "Deoxiit" and get those back to life.
otherwise, go get a climate control assembly from junkyard or ebay, replace the whole unit.
good luck...