thanks lenore...
This morning I discovered that if the thermostat is set low enough (below cabin temp) when first started it operates properly and blows cold air. I believe the a/c was even cycling. When I raise the thermostat (above cabin temp) and go to heat everything works correctly, hot air from dash to dash/floor to floor if temp differential is sufficient. However, when I lower the thermostat to below cabin temp again, only hot air comes out (even though the venting operates correctly, ie. foor to floor/dash to dash).
If I turn the system OFF, I hear what sounds like some sort of flap fall, turning the system back on usually works fine until you need heat and the cycle starts over again.
Oh, one thing that has happened since we got the vehicle (2yrs ago) is the a/c panel light comes on whenever you go to AUTO mode, regardless of the thermostat setting or the temperature. It has never been a problem, so I assumed it was normal.
I'm hoping to continue troubleshooting this problem with help from the forums.
Thanks again...
Russ