Heater will not switch out of defrost. Auto hubs will not engage. Buzzing noise under the dash when the heater and fan are set to off. Acts like a vacuum problem. Heater works 4 wheel seems to work with the hubs manually locked. What's wrong and how do I fix it? F-250 diesel. Happened once before, easy fix, dealer charged $250 and no parts.
Saturday, November 3rd, 2012 AT 11:46 PM