If the control (blower switch) you are referring to is for the Air Flow (Fresh Air) heater, and you are referring to the cable-operated control (for defrost), you are describing the correct mounting location. However, the control that I am thinking of does not turn the motor on/off, it turns a "flapper".
If the blower switch is an electrical switch for the fan motor, it is also located in about the same area.
I have a factory installation manual for a 48 Air Flow (Fresh Air) heater and I will look to see if it has a picture diagram for control-locations in a 2-ton truck.
Tim
