should I return the the new altenator? on 1990 Chevrolet Corsica

I replaced the bad alternator with a new one but the checks say the voltage is bad... Should I return the new one I put on the car and trade it for a different one????

Asked by for the 1990 Chevrolet Corsica
Usually the auto parts store has a alternator test machine but its not uncommon for a rebuilt alternator to be defective right out of the box, If they have a test machine have them but it on there and see if its bad.
Even a new alternator can be bad right out of the box, have them test it to see if its bad.
the Altenator was a NEW one not rebuilt
1 more answer
Also check all of the wires and connectors for damage. Make sure the grounds are secure as well. Is the battery fully charged?