98 Grand Marquis Auto Temperature control problem

[cloudman]

My floor button light on the auto temp. control in the dash went dark. Then I started to get warm air at 60 degrees or luke warm air at 90 degrees. The AC compressor runs all the time even in the 90 degree selection. In effect I cannot get hot air from the dash or floor unless I disconnect the AC compressor. There are no freon issues or radiator problems.
Since the floor control button is faulty, the self dianostics on the ATC will not initiate. Can anyone tell me if the control head in the dash can be removed without removing the dash itself. Any ideas for a do it yourself fix on this problem. All the lights on the control light up and I hear some damper sounds when the temp is run up or down. The floor function does nothing and stays dark. The defrost/floor switch does light up and appears to work.
Thanks for any advice.