If it's a vent hose it doesn't go anywhere.
on my 1999 ford mercury villager its on top of transmission under the van
In the bottom of the transmission pan.
How do you change the thermostat in 1999 Mercury Villager
Yes.
Front of the transmission, the thing the shift cable attaches to.
The speed sensor is on the top rear of the transmission. It is held on by one screw.
According to the 1999 Mercury Villager Owner Guide : ( 20.0 US. gallons )
In the engine.
134-A
No, no room.
The speed sensor is on the top back corner of the transmission housing. It is held down by one screw.
In the fuel tank.