2009 E70 Front Heater Not Working - Need Help

Team,

(2009 BMW X5 35D.)

Problem:
The front blower for both heat and AC is not working at all. It slowly had gotten worse with blowing then quit altogether. Rear heat and blower are working when I check off (Use Front Settings. I'm stumped on diagnosis and parts and there is no recall on this issue. I have researched the solution and came up with four possible parts myself but it may be a combination or something else entirely. Also not sure where to locate some of the items like the heater Heater Relay Switch.

Parts are:
1) Heater Relay Switch. (BMW Part Cost $11.) Problem is I don't know where to find it. Any help here?
2) Blower Motor Resistor/Regulator. Also called FSU Final Stage Unit. (BMW Part Cost $122.)
3) Blower Motor. Blower Motor Fan. Cost $160.
4) Heater Control Valve. Cost $40.

Questions:
a) Do you know what could possibly be causing this and what parts to try first? I am leaning towards the heater Relay Switch and Blower Motor Resistor/Regulator first.
b) Do you know of any possible solution to this problem?
c) Do you know where to find a good repair manual. I have downloaded 3 now and none of them address the troubleshooting of this.
d) Would a computer scanner work to diagnose? I have a friend/mechanic who is doing the work and he has one but not sure if this will show up as an error code or not.

Any help with diagnosing or repairing would be much appreciated. I will post the solution once I get it repaired. Thank you so much.

Edward

:dunno: