Defroster/Heater Core

Blower seems to be working ok, but there is very little air coming out of the defroster/vents...I am also smelling antifreeze inside the vehicle whe the heat is running...I pulled down the glove box & I cannot visually see any leaks...I can see the accuator driven motor & door are working normally...any ideas befire I tear into the heater core???Thanks..