hi i have a 98 f150 4.6 4x4 i have a problem with my 4x4. My 4x4 light stays on it will not go off and my truck wont engage into 4 wheel drive. I have checked a lot of things and i did figure out a way to get it to engage. under the hood passenger side you have where your vacuum lines hook up i have no clue of the name of the part they hook into but any way i can unhook both lines and then plug one into the place of the other leaving one unhooked and then my 4 wheel drive will engage. then to take out of 4 wheel i just hook the lines back up like normal but my light on the dash stays on. Does anyone have a clue why the 4 wheel drive doesnt engage and whats the deal with the light