Okay i have a 91 305 tpi and whenever i turn the key to accessory, you can hear the blower motor start blowing a little, but when i turn the fan to different speeds like vent, max, and that stuff, the blowing does not change speed or location or anything. Could this be a blower motor just going out, or the vacuum switch in the dash that controls everything for it. Any and all help is appreciated, thanks!

 

Unless the slider is set to OFF, the blower will run at whatever speed you are set at - the fan switch just controls the speed, not the on/off function of the blower.

If it's not switching between different vent locations, more than likely it's a vacuum leak as you mentioned, although there is also a door that is actuated by one of the sliders, but I'm pretty sure it's just the door that opens/closes off the heater core, and is controlled by the warm/cold slider and not the vent selector.