XYZ switch vac/vent hose?

[LarryR914]

Hi - I've had some problems with the gearbox fault warning and then the associated shifting, cycling gear status, etc. Reading the forums, one of the most common causes for this is the battery. I've changed it and that seems to have helped. However, here is my question: What does the hose that comes off the switch do? Last week mine was "found" to be disconnected by a shop (non-LR), that was resealing the oil pan, and they removed it. They only saw where it mounted on the firewall and didn't spend a lot of time trying to figure out where it connected. Today while looking at a XYZ switch picture, I noticed that the switch has a pigtail plug and also what looks like a hose and valve, so that reminded me of this hose that was taken off while getting the oil pan sealed! I thought I had put the hose with its check valve(?) in the back of the truck, but I am not finding it now. The truck is driving ok and shifting ok, but there has been a time or two when it felt "funny". So if someone has an answer and advice, I'd like to hear from you.
Thanks!
Larry
97 RR 4.0

[dirtyduk]

The hose is a simple vent, if you leave it off water will get in the xyz switch and cause havoc, your ac drains will most likley be dripping right about where the hose was, if you lost it just get some vaccum hose to replace it.

[LarryR914]

Sorry just now getting back to the fourm - with a different issue.

This vent hose is critical to have in place. After mine was disconnected and removed, the XYZ switch failed, due to water getting in thru this opening. Easy (but expensive) repair.
thanks