I have a 1994 Chevy 3500 6.5L. When I bought the truck the front drive shaft was out of it. I put the drive shaft back in and when you put it in 4x4 the drive shafts both turn. However, the front wheels don’t lock.

I have checked all over, found a vacuum hose I’m assuming. It hooks right above a plug on the transfer case. I followed it up past the transmission and it was zip tied to a bolt hole. I’m assuming it has another piece that is supposed to attach to it and go someplace. I have no clue where this hose would go too. Or if anyone has some detailed information on what could possibly be wrong.

Any help would be great!