have a 2004 ford escape 3.0l v6 2wd, i have replaced the Alternator installed a new battery, the car will only run on jumper cables or a good charged battery. I took the alternator back off had it tested and tested good. So i check the voltage with a meter and get 11.98 an declining due to no charge any help or thoughts on were to turn next

Might want to check continuity of the battery+ wire that connects alternator to battery. Some have a fusible link that can electrically open up.

Tom I had the alternator and battery both tested came back good i bought them new Bob i looked but i do not see any fusible link

If it has a fusible link it will be located "in line" as part of the wire that runs from the alternator to the battery.

Check all battery wires wires to stater and alternator