Discussion Starter · #1 ·
My dad has a 2003.5 6.0 with on-the-fly 4x4 engage. He told me today that the 4x4 will not engage. Also his a/c only blows on defrost until he starts moving, that's what I think he said. I told him it may have something to do with the vacuum pump. Because I know that those hubs are engaged by vacuum. If y'all could help me out that would be great!