I emailed R&S for a service manual and they replied with "No, we don't offer them for proprietary reasons". So I'm trying to see if someone has the manual/schematics for it because I know that is not strictly true.
Added photos for immediate problem. Power resistor for low speed fan burned up so only turns on when pretty hot. Goes across this temp switch to drop the 250Vac. I have some resistors ordered but no idea what is right, or if any will fit well.