Why is my blower motor only working on high speed?

Sounds like a blower motor resister failure, it is located in the rear of the engine compartment passenger side firewall, four wire connector,(yellow/green, black, orange/black, light green/white) very easy to replace. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online