Air conditioner blower works on normal but does not increase fan speed on Max.

What is its value and where can I locate it?

approx 120.00 plus diag fee if there is any

Thanks for the idea. I found the wiring diagrams for the climate control and defrosters as well as a vacuum diagram at http://www.taurusclub.com/forum/116-aesthetics-interior-wheels-tires/136066-1997-wiring-diagram.html. I will have to check it out. I am wondering if it is the knob not being able to make the last detent on the selector because it has a crack in it. I will have to get a set of pliers and see if it is turned all of the way or not. It could possibly be the switch. Do you know what the value of the resistor should read on an ohm meter?