interior fan problem

[loudizzle]

i have a 2003 yukon. Ac and heater work great, just the problem i am having is that the fan doesn't really start to work until i have it set to position 3. Also if i have it set to 2 and i an driving about 45 miles n hr you can start to feel it, but when i come to a stop then its like it is off. I don't know a whole lot about cars, i did check the fuses and they are good. Any help would be great.

Thanks in advance, lewis b.

[yukon6inchlift]

i've known several people with this prob. all the 90 models had fan probs, didnt know it still was an issue. u may think i'm crazy but kick/ hit the fan box and it will come on. (the big black box on pass side under dash)