the a/c heater will only blow out the defrost by the front windsheld. i have never had the happen before.is it somthing simple or should i take it in

 

When you say it will only blow out the defrost do you mean no air comes out anywhere else?

This may be a simple switch problem located on the **** itself.

 

Does the damper move to other positions like vent or floor? If not, start looking for a vaccum leak in the vaccum operated damper system. Zcould be just a line that got knocked loose under the dash. Also check the hard line under the hood and the vaccum canister.