GM-GMC: heater fan, blower motor resistor, gmc sierra

Question
I have a 2003 GMC Sierra Duramax Diesel. I just recently had an after market remote start put in. (Viper brand)It has only been in the truck for 2 weeks. I discovered this morning that when I turn off the ignition, the heater fan stays on. Even if you turn down the fan speed or turn off the heater power on the dash, there is no difference, it just stays on high. I have turned switched off the remote start but it still stays on. I am hoping you have some ideas for the problem. Thanks.

Answer
I had a similar question from a gentleman with a tahoe.  I suggested that it was likely the fan motor itself or the blower motor resistor.  If I remember correctly he updated the post and said it was the blower motor itself that was faulty.  
Check the blower motor resistor and the blower motor.  They are located on the passenger side under a shroud/cover.  I don't think this concern is related to the remote starter.
Hope this helps