hello all
I have an issue with my 2009 Ford F-250 super Duty, 5.4 L
my truck will not take 4 wheel drive, external hub locks are rolling clockwise into the lock position. The dial switch in the dash is indicating that it in 4 wheel drive HI. still no responce.. also there is no sounds of anything turning on (Silents).

I have checked the vacunm lines for the Hub locks and alls well, traced the vac line to a module on the inside of the engine compartment , the module has 3 ports connectors in one unit , tested with a light and found that only one port has power ,the center port. Tried turning on the 4 by 4 switch and checking for power on the module, no change.

is it possible for one or both Hub locks are broken?
how can i test for the hub lock is working?

 

You're pretty much bypassing the vaccum actuation when you manually turn them. The fact it's saying it's in 4Hi on the dash makes it sound like the actuator is turning it into the correct selection on the transfer case....how are you sure it's not working? If you try turning tight in a parking lot, you should feel a slight binding / engagement from the front wheels.

 

I tried my 4 by 4 on a semi-slight incline and only the rear wheels are spinning, I will try the sharp turning action this evening. Thanks


just tried the sharp turn and there is no resistance, free flow

 

How do you determine which lock hub isnt working?

 

Oh sorry, I misread your first post. I thought you said the 4x4 light was coming on the dash. Sounds like when you switch to 4x4 on the dial, the actuator is not shifting the transfer case to 4x4, nor illuminating the light.

I'm unfamiliar with the 2009 model year. Most likely the wiring to actuator or the actuator itself (that is mounted on transfer case) is malfunctioning.