i have a 92 Cherokee sport and when i put the heat on full blast, i can here that the fans blower hard but theirs not much coming out of the vents

 

Is all the air going out the defrost?

 

nope, if u put it on defrost then air comes out

 

Heater core probably.. Can be flushed/back flushed to clean out. Pita if it's gotta be replaced..

 

Really vauge on what your asking here try a bit harder on what you need ,I think you mean not much force for the air coming from vents, If so the heater core has nothing to do with the force of air ,I would think you have a door part open when it should be closed.

 

I agree. It sounds like one of the vacuum motors that actuate the doors has a vacuum leak or is disconnected.

 

hey sorry was in a rush when i was doing it,so when i put it on any fan speed mode not much air comes out of any of the vents.(i can hear that the fan is on full blast so i know the fan works) ,doesnt matter if i change it to vent or heat or defrost not much air comes out ,how do i fix it

 

Do this:
Grab a flashlight and poke your noggin up under the passenger side dash. Move the heater controls until you see a door open exposing the blower fan. It's possible there is something in the squirrel cage of the fan. I have had rodents get in and pack the cage with carpet padding.

 

ok did that no door opened but i could push open a flap with foam on it and see the blower fan nothing their ,now next 2 it their was some wires that went into the heater core ,poped that of and found some one filled in-front of the heater core with some type of fluff ,so took it all out and now all the air is going out the defroster ,what do i do now?