Get a multi meter and find which wire at the switch has 12 volts when the ignition switch is in the ACC position. That is the fused feed for the switch which in turn feeds the three speed blower switch. Trace the wires back from the blower motor resistor pin A is low speed, pin B is med speed, pin C is the high speed setting.
This is for a '94 YJ so the wire colors may be different but the layout should be the same.
"Taking care of our veterans is a cost of war. If you can spend six trillion dollars sending people to war, you can spend a few billion dollars taking care of them when they come home"
Sen. Bernie Sanders (I-Vt.)
If what doesn't kill you, makes you stronger, I should be able to bench press a Grand Cherokee by now!