I replaced the heater core on my dodge Dakota a couple of weeks ago and when I put everything back in I had heat again but only in defrost and on my feet. under the drivers side there is a black hose coming out of the box holding the heater core is that the reason hat does not come out of the vents? and if so were would the hose go?

 

Pic of the hose?

Do your vents switch at all? If not, I suspect your hose is a vacuum line......

 

the vents will switch from defrost to the floor but the air won't come through the dash

 

That line likely goes to another actuator somewhere then. Not sure exactly where it is in your truck......