Heater problem

So I was playing with the heater nobs seeing what moved what and so on. The heater fan won't turn off.
So correct me if I am wrong but I beleive its the switch behind the dash that controls the fan (the other 2 switches are under the hood) so if the problem is just this being stuck shouldn't I beable to reach up and do it myself with out the nob. I tried that and it didn't work. Let me know if any of you have had this problem and how to fixxed it. Thanks

 

Hi crujones,
Are your heater controls cable or vacuum line? Got a pic?

 

they don't seem to be vacum lines. They are nobs that pull out a cable. I will try to get some pics tommarrow.

 

The center knob/switch twists for off/lo/hi. It may be stuck in the low or high position.

 

I didnt get a chance to get pics so it will have to wait until may when I get out of school but is that the one that connects under the dash? The other two are under the hood and both are off. The one under the hood is tuff to get to but I tried pushing/pulling it with no luck. Thanks for you help.