Blower motor wiring?

Replace the fan motor. The resistors themselves are not what actually burns out. There's a thermal fuse built into the assembly. That is what burns out when the motor draws too much current. That happens when a motor has tight bearings.

In the highest speed setting, a relay is switched in that completely bypasses the resistor assembly to handle the very high current. That's why GM heater fans will still work on that one speed when the resistor fuse burns out.