A/C at driver's side - wrong servo?
 

I bought used GS450h and I found out driver's vents only blow cold air - no matter what temperature I set on A/C. Passanger's side is ok, no problem there.
As I browsed this forum I found out it is most probably due to faulty servo mixing cold and hot air. May my problem be really caused by faulty servo?
If so, can somebody confirm part numbers for these servos?
I found schematics here and it looks like 87106L (part number 8710630480) is what I need. Correct?
Thanks!