I had the same problem...no heat no matter what setting I used. Fan worked and A/C was fine. I don't have the time or know how to try the repair on my own so I took it to local mechanic. Found out it was drivers side actuator that was broken. It cost me $250 ($75 for part) to have him replace and now all settings work great.

 

Look at the parts manual.

It appears that the actuators are behind the radio.
Can one remove the radio assembly and access the actuators to replace them? Or does more stuff need to come off to gain access.

 

Might have looked at how OLD this thread is before posting in it.

 

Yet here I am, 7 YEARS later and it's still being referenced.
Thx for the info people.

 

Believe it or not, you can READ old threads and do not have to post anything in them. It usually only takes one person to change a light bulb, but then again.............