heating system malfunctioning

i have a 2001 grand prix gt the heating system is shutting off with out me turning the dial off as well as the dial will no longer on numbers 1-4 it will only work on 5 .
what could be causing these types of problems and how hard are they to fix?

Sounds like a blower motor resistor gone bad.

Hope this helps.....

http://www.clubgp.com/newforum/tm.asp?m=2075435&appid=&p=&mpage=1&key=blower%2Cmotor%2Cresistor%2Cwrite&language=single&tmode=&smode=&s=#2139218