1993 GMC Jimmy air and heat problems?

[oalex16x]

i just bought a 1993 gmc jimmy and at first the heat and air worked fine but now all of a sudden neither work. i can hear and see it switch over from heat to air or visa versa but no air actually comes out through the vents if i get going fast then it will blow out a little bit but not enough to heat my vehicle. any ideas of why

 

[Vacdaddyt]

No a/c ,heat

Is the noise the dampers or the fan? The fan probably stopped working, does it sound like the fan changes noise levels when stopped and changing the speed settings? The fuse needs to be checked first and then the resistor assembly, usually when the resistor fails so there is only high, if all are good then the fan motor failed.
Good luck and keep us posted.