After checking fuses this would be the next place I would look.
Be sure to post the results, or ask for more help if this don't fit your problem. The location of the resister is described at the bottom of the first post
I have checked the fuses and switched that one with one that I know works and it still didn't work. We have checked if the fan still works by attaching an outside source and it does. I have looked at a few other forums and many of them think it is the blower relay. I have a new relay but we can't locate it. If anyone knows where that relay is please let me know
There is no power going from the switch to the fan so it will not turn on at all
The switch is not supposed to supply power to the motor. The switch is installed in the ground side of the motor circuit and is intended to change the resistance of the ground (low side) circuit (via the blower resistor) to change the current flow through the motor and hence its speed.
Locate the blower motor connector. One lead should be battery voltage whenever the blower should be operating. The other lead should measure anywhere from zero when the switch is in HIGH to several volts when in lower speed settings.
If you have battery voltage on one lead but zero volts in all switch settings on the other, the blower motor is bad.
If neither lead has power when it should, check the blower motor relay located in Aux relay box #4.