vacuum lines at transfer case 95 jimmy 4.3

Ok I just replaced a dry rotted vacuum line that goes from under the battery to the transfer case. Problem is I think I pulled one of the other lines loose from somewhere. Ok so one goes up under the battery. Another goes up to the vacuum tank I think. The last one goes to a y connector another line from the y connector attaches above the tansfer case and another (bigger) line goes from the y over the transmission pan and is hanging there with a little peice to put two hoses together in it. Where does this attach to? Anybody know?

The switch on the tranfer case has 3 ports. 1 goes to engine vacuum,1 goes to the accuator under the battery(to lock in the front diff.) -the other line tee's in with the trans and transfer case vent hose(to allow the accuator for the front diff. to release).Kind of a screwy system,but it works.