Pontiac Repair: Blower fan does not operate on 1,2,3, pontiac montana, passanger side

Question
I have a 1999 Pontiac Montana and the blower fan for the AC/heater only works on level 4 & 5. When i try to put it on levels 1,2, or 3 nothing happens. Can you give me a few pointers on what I need to check or should I take it to the shop?

Answer
Hi
The Blower resistor, located on the passanger side close to the blower motor is at fault.
Check the harness going to it also for burnt wires.
I would say it is  4 TO 6 on a scale of diffuculty due to the upside down position needed to gain access to it.
If more help is needed, let me know.
Good Luck.
Pawl