Catalyzes the acetylation of dTDP-fucosamine (dTDP-4-amino-4,6-dideoxy-D-galactose) to dTDP-Fuc4NAc, which is utilized in the biosynthesis of the enterobacterial common antigen (ECA). acetyl-CoA + dTDP-4-amino-4,6-dideoxy-alpha-D-galactose = CoA + dTDP-4-acetamido-4,6-dideoxy-alpha-D-galactose + H(+) Bacterial outer membrane biogenesis; enterobacterial common antigen biosynthesis. Homodimer. Belongs to the WecD family. Truncated N-terminus. Truncated N-terminus.