Charles,
There is a Resistor that controls all of the Blower motor speeds except "High" that is likely at fault. It is located on the firewall, under the hood, just to the right of the engine air intake. List price is $26.37 (our price is $23.73)
Where are you at in Ohio? We are in Cincinnati.....
Travis DePew
www.RubberDuck4x4.com
(513) 617-0913
"Don't go in without protection"