4x4 will not engage on 1995 Dodge Ram 1500

4x4 will not engage in front axle assy. Any suggestions?

Asked by for the 1995 Dodge Ram 1500
The 4 wheel drive is vacuum controlled through the transmission. It has a shift actuator on the front axle sometimes the sifter can stick if it is not used somewhat frequently. Or is it that the light just doesn't come on? Cause the truck should hop when the 4 Wheel drive is engaged and you turn sharply
1 more answer
usually a vacumme leak start at the hard plastic lines running from passanger side of the manifold to the transmission. they are brittle and break easily