So I have a 2000 7.3l diesel SMB with the 46 gallon TF tank and there appears to be an extra hose that is not currently being used and I am not sure what it's for. Along the inside of the driver's side frame rail there are what appear to be 2 fuel lines(?) that are connected together in the rear of the van with a Y shaped plastic fitting. As you follow the lines towards the front of the van, one line turns and heads for the top of the TF tank where the fuel pump sits. The other one keeps heading towards the front of the van and as it gets roughly where the drivers seat is, it ends with what looks like the male end. However, it is not capped it is just sitting there open ended. Any ideas what this should/did connect to?
Y fitting towards the rear of the van:
Uncapped end near front of van: