My heater blows cold air in front and hot air in back

I have a 1999 Ford Windstar and my heater when turned on will only blow cold air in the front and makes a funny clicking noise. The back heater works fine. If you can help me, please send pictures of how to get to the Blend Door Actuator from the glove box or from anywhere else. Winter is coming on here in Oklahoma and I need to drive this vehicle. Thanks in advance for your help.

You will see last photos on page 1 and some more on page 2
Push the 2 ends of the glove box in so the stop bumpers will clear sides and glove box will drop down you can see in from the side. Also stereo will need to http://community.webshots.com/album/556939487VdTPOVbe pulled.

Start here:
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http://www.automotiveforums.com/vbulletin/showthread.php?t=308775&highlight=phordguy
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... and if you find that you have blend door problems, go here:
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http://www.automotiveforums.com/vbulletin/showthread.php?t=522563&highlight=phordguy

ok try this one.. http://community.webshots.com/album/561205362eKXCZO

My front actuator went; followed the other threads on this; thanks. Now I need to also fix the rear heater; only cold comes out of rear; is this an actuator problem as well? I've read some incomplete threads about vacuum actuators, etc. but any help on this would be appreciated please

Your '99 has electric actuators. All will be revealed when you remove the rear LH inner-lower plastic trim panel ... just behind door opening.

Thanks for all you input re: actuators and related items. Just quick answer; how to pop the rear panel over the actuators, etc without marking the panel? No externally accessible clips or screws are visible

thanks