I am not sure what you are asking in this question but many vehicles were produced around that year with vacuum operated 4wd actuators.
All of them have been changed to electric or manual because of the problems they have. If you have a bad one just purchase the correct size new hose from an auto parts store and replace any that are old or cracked, The lines will run from the front hubs to an actuator nearby.
My suggestion would be to buy the replacement manual locking, or an electric kit, the favorite being the manual. It is much better to have to get out and lock your hubs than to have no 4wd at all when you need it, 4wd vehicles are meant to go offroad, through snow and water which are both enemies to the electric components, and to the seals and hoses of a vacuum operated unit.
There isn't a vacuum line going to the regulator on a 1998 Dodge Caravan.
You can find a vacuum line diagram for a 1989 Dodge Dakota by checking the owner's manual. You can also find them at different auto part retail stores.
In the line that hooks to the passenger side of the intake manifold.
That is an access port to pressure test the evaporative emissions system.
No.No.
they exist
The vacuum diagram for a 1998 Ford F150 is located in the service manual. It details how each vacuum line is routed, where the line is attached, and its function.
we need a vacuum diagram for replacement 1997 dodge 1500 4x4
vacuum line diagram
Try Google
In most cases it is either a leaking heater core or a plugged evaporator drain line Could be a bad windshield seal
Alot of cruise control units have a vacuum line going to them. Check this line see if there is any leaks or such.