My hot/cold temp. dial not working. At first it was blowing only cold air on hot & cold. My boyfriend tapped on the thermostat case in the engine and nowit blows only hot airon hot & cold. Very strange. If you have any idea what this is, please let me know. I drive a 2003Ford Explorer. Thanks for your help.

 

Does it overheat? Try changing the thermostat. I suspect that the problemis more likely in the heater control. There is a blending valve inside of the temperature control box. It opens when you turn it to hot, and closes when you turn it to cold. There are plastic gears that open and close the valve when you turn the ****.The gears are cheap, andare NOTORIOUS for breaking in Exploders and Tauruses. To replace the gears you have to REMOVE the dash and temperature control unit. This is a full day job,and will be very expensive.Unfortunately yours broke closed (cold). If it had broken open (hot) you could cut off the heat in the summer by placing a jumper hose with a petcock (**** to turn on/off) across the heater core ports.I know, this is not good news. MistrFixit

 

Thanks, Mistrfixit. I made an appointment with my dealer.They are going to let me know if it is covered under my extended warranty (fingers crossed). I notice now when I turn mytemp. ****, I hear a clicking in my dash board but it stops after about 6 clicks. Thought maybe it couldbe my blend door. I really appreciate your input and help. Thanks, again!