I have finished the Sanctuary quest to provide food, beds, clean water, and defenses. After all of that is done Sturges tells me that Preston wants to talk. Whenever I try to talk to Preston he just looks at me and gives me a short quote like, thank god it's not raining. I really need help with this because I know he is needed for future quests. I also know he is a companion that can tag along with you. Someone please help!
This is very similar to a known bug listed on Preston Garvey's wiki page. There are some fixes listed there too that may help to resolve the issue.
From the site:
PC - This can be fixed on PC by opening the console, selecting Preston Garvey and inputting removefac 00075d56.
XboxOne - A possible fix for this is to have Preston as a companion while initiating the assault on the Castle.
XboxOne - Another possible fix is if the Sole Survivor sides with The Minutemen against The Institute in the endgame. After activating the bomb in The Nuclear Option, Preston will talk and can be asked to follow the Sole Survivor. [verification needed]
XboxOne - Another possible fix is if you attach a generator to the conduits and wires already setup in the castle the power requirements will turn green in the workshop menu and he will be able to act normally again. [verified]
I had this problem for a while, if I remember correctly he wouldn't talk to me until I built Mama Murphy's chair. Check your quest log in the Pip-Boy, it should tell you if there's still something you need to do. If the problem is Mama Murphy's chair, you can find it in the workshop menu (under Special) and you need to build it to proceed with the quest. After I'd built her chair I could have the conversation with Preston to complete the quest.
Yes Sturges said the same to me, over and over. I found that once you complete some of the Minuteman quests then he will speak to you. You can tell when he or others are ready to talk when the little yellow balloon is displayed over their heads. This means that a character has something to say and usually opens up other quests/missions in the game. So just keep playing and the issue gets resolved. Hope that helps :)