You have to go and speak with dad and get the fuses from him.
He gives you the fuses you run all the way back down and you go to the A1 fuses and add the new ones.
Then you are asked to turn on the power in the Main frame which is located behind the Electronicly locked door which opens with the fuses.
Once you activate the Main frame you are asked to go into the intake pipes and clear them up because they are clogged and as you are doing that you will see some enclave soilders hopping out of a Helicopter.
You don't have to face many of them so don't be nervous if you got bad guns.
You get the door unlocked and then you go down the pipe and out which there is once Enclave soilder standing on the top platform i belive i remember.
Once you've gone through the top door there should be a enclave soilder inside the Jefferson Memorial and gift shop.
Then you run back into the purification center and you water your father die.
Then you speak to Doctor Li and she says you've got to get out of there there will be more soilders soon.
So you go into the Talf Tunnel and you get stopped by Ghouls and then Garza happens to have heart problems so if your speech is good you can make him stay behind (Which i did, but Garza was dead far before that point)
And you just continue down the tunnel to the Brother of Steel or something like that's base.
