Land Rover Repair: 2001 Range Rover blender motor prob?, heater core, hot day

Question
I believe I might have a blender motor problem but not sure.
Passenger side blows HOT air only , driver is basically at vent.
While changing my heater core o-rings (also might be cause for the wet passenger side floor that I noticed someone else asked recently), I was going to change the blender motors(3) but before I do that I noticed that the air conditioning takes a minute(60 sec.) to engage after I press the button (very similar to the heat) , but shouldn't the a/c start right away?  I can hear the compressor kick in twice before the blowers start. Might this be a sensor?
Also had to remove the duct from the passenger side and noticed that box right behind the heater core is blowing cold air but as the engine warms up gets over powered by the heat.

Answer
It does sound like you have a blend door problem.  As to the other issues . . .  on a hot day it may take a minute for the air conditioner to generate cold air even though the compressor starts right away, and your comments about air flow are consistent with a blend door problem