im having problems with my 4x4 it does not engage when i switch to 4hi the light never comes on on the dash and you dont hear anything same thing when i switch to 4low after i put the truck in neutrul and foot on the brake nothing happens no light no noise. i checked the vacum lines going into each hub and when the truck is runing theres suction in the vacum line thats bigger the smaller one has nothing ,when switched to 4hi or 4lo nothing changes there still suction in the line. any help would be appreciated.my truck is 2005 f-150 xlt 4x4 4.6 v8

 

Have you checked your 4x4 fuses?

 

i checked all the fuses that are related to the 4x4 system their all fine, i forgot to mention that when i start the truck the light for the 4x4 hi and lo do come on for few second when the engine is started but when you try to switch them on nothing happens

 

Stupid question, but yes, it's related...Does your compressor kick on when you select defrost?

 

the compressor does kick in

 

I have a similar problem and really know little about the new fords, I have been disabled for 7 years and only recently bought this truck, here is the post I entered in another forum, I assume its the same problem.
"I am having a problem with my 2005 f-150 4x4. it has the triton 5.4l with a 3 speed auto with O/D. when I try to shift from 2H to 4H on the fly it will not engage and if the rear wheels spin on some ice, there is a small grinding noise from the front end, however, if I stop and try to shift into 4h it still will not, I must first stop fully, then put it in neutral, then shift to 4h, then 4l and when I hear the front hubs engage, I move about 50 feet forward then stop and put in in neutral again then into 4h and its engaged,if I slip into 2h it shifts but I have to go through the whole procedure again to go into 4h, its really frustrating while moose hunting in the Canadian north."

 

mine is different problem since my 4x4 does not kick in at all no light when switching to 4hi or 4lo. i was told that the solenoids go on these trucks but i do have vacum on the lines leading to the hubs i was told that when the engine is runing you should have vacum pushing air out of the line but on mine when the engine is runing i have suction in the line,im starting to think that it might be the motor that ingages the transfer case that might have went bad,

 

well, I reckon its time to start getting into the guts of this truck,, my last one was a 95 with a 5 speed 302 4x4 best truck I ever owned but had to sell it after it sat for 7 years, had to buy an automatic because of a gimped up leg from an industrial accident.
so I understand there are solenoids to engage the front shaft and fuses for the solenoids? Also a compressor, what does it operate in the 4wd system?

 

Well, that shoots my theory to hell then...Sorry...Don't know.

 

i had the same problem the guy had with nothing and it turned out to be the actuator motor that engages in the transfer case motor was burned up

 

I have had this problem for 2 years. The first 2 times I took it in they could find nothing wrong. It always happened when it was damp out. It would happen for a day or two , then start working again. I now have 60K and they tell me I have to replace a motor? They tell me they have had problems, and have a revised one now. It will cost approx $750 to repair.

 

That's what mine was. Same situation - the light wouldn't come on and it would stay in 2wd. The transfer case motor was bad from the 1st day I put it in 4WD (or tried to I should say). It was replaced under warranty and I have NOT had any problems since.

My first attempt at using 4WD on this truck was towing a car in a snowstorm. Really would have been nice for the 4WD to have worked!

2005 XLT 4X4 crew cab.

 

I second that. Check the electric transfer motor. Its super easy to change yourself. Check Rockauto.com, it has refurbished ones listed as $141 dollars. I doubt you'll see it that cheap at the local stealership's parts department.
this is what the culprit looks like:


its screws right into the backside of the transfer case. If the motor is fried or the harness is unplugged 4x4 will not work and no indicator lights. Check the harness first. I've heard that sometimes the motors just seize up and whacking it with a hammer then trying to shift into 4x4 works.

 

that looks identical to the shift motors I've replaced in several 92-96 F-150's


got all of mine from Wrecking Yards for under $100 though.

 

See this TSB. The part in the TSB is ~$30, and will fix your 4x4



https://www.ford-trucks.com/tsb/full...hp?tsb=06-8-15