F150allseasons

So I read a few threads where their cruise control wasnt working. One said that if the brake lights dont work then it wont work either. So I checked that out and mine work. Then someone said that if your master cylinder isnt full then the CC wont work. I did have to add some fluid but my CC still doesnt work. Before I did any of this, I looked in the owners manual and found where my fuse could give me trouble. I pulled it out and see that it works too.
I am running out of options. Does anyone know what I should do next?