Fallout 4 FUSION CORE Location and Power Armor
Make your way to the “Museum of Freedom”, which will automatically put you in a quest to kill enemies. After you’re done, talk to the people inside and they will mention a Power Armor that you can use on the roof. It will need a Fusion Core to work.
Luckily there is one on the bottom floor of the building. At the start of the staircase is a generator behind a gate. Lockpick it and remove the Fusion Core.
Now go all the way up to the roof of the Museum of Freedom and put the Fusion Core inside the Power Armor to activate it. From here on out, it’s yours. Have fun.