Hello:

I just purchased a 2006 XLT 4x4 5.4L with manual climate control and am having intermittent problems controlling the heat. At times, the heat control **** will have no effect at all on the temperature - the air will blow either hot or cold no matter the position. At other times, the air will be cold when the **** is in the blue zone and hot when in the red zone, but I cannot achieve anything in between. The other night the air was cold only and I could only get hot air after shutting down the engine and restarting the truck. Today it was working fine - I was able to gradually adjust the temperature between the two extremes.

I have done extensive online searching and the "blend door" issue keeps popping up. However, not too many people have mentioned it as a intermittent problem and it doesn't seem to occur in anything newer a than a 2003. The truck is going to Ford on Tuesday but I'm concerned that the problem won't replicate itself while it's there, which will be aggravating for both of us. Does anyone have any ideas or similar experiences that I might mention to the service department?

Thanks for any help,

Chris