Nope!Did you figure anything out?
What year is this? I think the hard dash Range Rovers have separate fans for heat and ac. You might just have a bad fan .
Your heater blower fan is cooked. Time for dash teardown.
Resistor pack OK since you have 3 speeds on the AC blower side. Switch OK since it controls fan speed OK. Heater fan motor has pooped out. Yes it spins when fed voltage but the armature is dead so it won't spin up.
LOLOLJust throw it at Sarek and write him a fat check