I have the same problem and when i took it to the dealership they replaceed the 4wd actuator. the noise returned the next day and when i took it back they told me that my grill was loose(do i look stupid or something?) i need help!!!!!!

Well from experience 99%. Of the time its not the actuator if it shifts into 4 lo and back to 4 hi. The book really sucks at this diagnosis. And if lights on buttons blink for 2 hi for a bit then stay in 4wd then u have to listen very carefully. When shifting from 4 hi. To 4 low the whine or growling noise from motor is heard. If, when shifting from 4 hi to 2wd this motor noise is heard, then actoator or wiring is the issue. If the time while 2wd light is blinking, ie: its trying to shift, no noise from motor or actuator is heard, then shift module has a burnt output. Now. Before replacing any of the components, if you have a schematic of this system, you would be confused on how any of it elworks even if you are a seasoned professional. I wouldn\'t bother 2 much with it as long as you theory inspect Evey millimeter of all the wires from actuator connector (on transfercase) to where it goes through metal and enters occupant compartment. If all wires look good. Lights in all 3, or 4 if u were lucky in neutral which means error, of the lights work, and if requested position is depressed on switch and motor tries to turn or does and clynks are heard , then actuator position switch is stuck and actuator is needing replaced, as not a serviceable assesembly, and I haven\'t had the ability to tear one apart. But if all lights work and when the selected switch button , example 4 WD, 2 WD or 4 lo, and no motor noise like heard when other shift works, them module is to blame. Now, I am a master mechanic with most experience at a gm dealership, I have fought with this system multiple times, and once I employed this diagnosis it has never failed me again. And the stack of 4wd shift modules in my bottom toolbox dawyer. Most times if won\'t shit at all night be actuator but not likely, 95% of the time when this issue rolled through dealership, it took a module to fix it.

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Did you do the work on the vacuum switch? The mechanic might have put it back on.

The problem is that you have a bad vaccum hub it's located down on the back side of the spindle. Very common ford problem!

Possible the vacuum bleed-off to the switch you installed isn't allowing it to completely disengage. Pull the bleed-off line from the new switch and see if it works. could be just a tight spot/bent closed in the bleed-off line or the vent plugged.

Return to the dealership for warranty if it failed in a day and half, that means they haven't repaired it for the price you paid.

just check on the front differential there is the actuation 4WD valve which is operated by means of vacuum. See whether you do have any vacuum leak,broken vacuum hose,or if the actuator itself does not work.

actuator may need service[lubed ]connection or wiring loose or damaged

check for problem circuit and 4wd actuator

Having the same exact problem but with my 1999 escalade. Thought it was the actuator bought a new one installed it transfer case would engage but front end wouldnt lock. Took it out of housing left it plugged in got a friend to go through all the 4wd for me and the plunger never moved out the actuator. Checked my wiring harness which is a four prong ann it had one hot prong like it is suppose to. Traced wires even replaced dash switch same problem. Taking it to local dealership tom to have it checked for codes. I was told it could be the transfercase actuator even though its workin that actuator is what sends power to the front to engage the actuator to lock the differential.

Sounds like your front actuator in the axle is not working..What you can do for now instead of buying a new one is remove the front actuator.It is a threaded in unit.Take a crescent wrench and remove it.Next find a big nut or bolt to put inside of it.Once you have it off you can jack the front end up put your finger inside of the hole where actuator goes.Rotate the front tires back and forth and till you can push the tab inside in.That will lock the front end .And the reason your putting the bolt or nut in there is to take up the space the actuator would normally would Push in..Remember your front axle is always going to be lock and you will still be able to unlock it with the push button.After you put the bolt in the hole screw the actuator back in.This will hold the bolt and keep your axle locked.........

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