A/C problem with digital temp control....need advice
2003 Excursion 4x2 6.0L with some pretty amazing HVAC problems.
Two weeks ago, the a/c stopped blowing cold and I could tell that the compressor clutch was toast. Burnt brake smell (pretty apparent) and the compressor would not engage at all. Since it's winter, I let it go and figured I would tackle it in a few months. we live in Arizona, so trust me when I say that I would have had it fixed before spring time here which means we would be approaching some pretty hot temps! Anyhow, the wife calls and tells me the EX died in flight and would only crank over as if the batteries were dead or dying. Of course I was 150 miles away and had to drop everything and rescue the missus just to find out that she was actually right! When I tried to crank the beast over, it acted like I was using a battery from a 10 year old Yugo and not the nice, new 850CCA batts I had installed just 2 months prior. Turns out the A/C compressor and clutch assembly were locked up solid and dragging the starter down enough to kill the engine while driving and preventing a restart! Unbelieveable!!!
No debris in the orifice tube, so I evacuated the system, flushed it, replaced the compressor, orifice tube and accumulator and blah blah blah.....all the stuff you are supposed to do when crazy stuff like this happens. FYI......changing the compressor on this vehicle is absolutely RIDICULOUS! After years of working on these types of things on top of the motor, having to remove one from underneath was a study in sailor language of all types. Ford engineers put the a/c compressor underneath and the oil filters on top of the motor....they only did this so people like me could say WTF were you thinking??
So now we have a nice running vehicle again and the a/c blows very chilly, but the new gremlin is a clicking/tapping sound from underneath the glove box. We either get cold air when the temp control is set to minimum, or hot air when it is set to anything over 75 degrees. No nice in between settings anymore.
Who can tell me what to look for and how I may go about fixing it? I suspect the blend door and it's components may be malfunctioning or one of my lovely children may have dropped something into the defroster vent (which would be small potatoes compared to some of the crap they have managed to do over the last 20 or so years).
I am interested in hearing any and all thoughts about what I should do to diagnose and repair this problem
Thank you in advance for any helpful advice anyone may provide.......