As I understand it, you're saying:
1 Fuses 1, 3, 23, and 37 are good.
2 The Ignition relay and the Blower relay are good.
3 The Blower speed switch is good.
4 The Blower motor is good.
5 The Resistor pack is good.
This leaves:
6 Blower Mode switch (off,panel,defrost...)
7 Grounds and other wiring.
If the mode switch is bad the blower relay will never turn on.