'02 Ranger Blower Motor question

The blower motor for the air/heat only works on high. I had the same problem in my old nissan altima and there was a simple $5 part under the dash that had to be replaced, i cant remember the name of the part. Is this likely the same problem? If so what is the name of the part & where is it located on the Ranger. If this isn't the problem what would it be? Any help is greatly appreciated.

http://www.automotiveforums.com/vbulletin/showthread.php?t=1058605 .....Mike