Hi all, I'm a long time viewer of this site but this is my first post.
I have a 2005 F150, 4.6L, 4x4 with the manual floor shifter.
My problem is this: I have no vacuum at the wheel hubs when in 2wd so the hubs are always locked in. I've found that there is vacuum up to the IWE solenoid but none coming out of the other side of the valve.

Here is what I've done so far: I replaced the IWE solenoid. I found 2 spots where the vacuum line was broken and replaced with spare vacuum line I had. I bypassed the solenoid with a piece of vacuum tubing and both wheels have vacuum after this. In this configuration the driver's half shaft freely rotates but the passenger's does not which may be a separate issue with that side's axle. I took a fluke and tested voltage at the electrical connector on the IWE solenoid and shifted between 2wd and 4H and saw no voltage in either case.

So it seems to me that the IWE solenoid is not receiving a signal to open, so my question is that there must be a switch somewhere that energizes/ deenergizes the IWE solenoid when I move the shift lever. Looking at the transfer case I see 2 electrical connections, one at the front and one at the back. Can anyone tell me if one of these is the switch I'm looking for and if not where it is? If you know what the name it would be under for the guy at the parts store to look up that would help too. If I'm off base here or anyone has any other ideas about what's going on please tell me.

Oh I just remembered also that the 4H doesn't work. It stopped working a year ago and I never thought anything of it other than the light probably burned out. I just checked and the 4 low light doesn't come on either. Not sure if any of that helps

Thanks in advanced.

 

Hope you check all your fuses and relays first.. if those are all good I would test the shift motor.. put 12vdc to it to test... if the shift motor works then troubleshoot the SOTF switch.

 

I replaced two 15 amp fuses and now the 4x4 light works. It still appears that the solenoid valve isn't operating. I believe the shift motor and sotf switch are for electric 4wd models. I have the manual shifter (no pushbutton/ switch) so those don't apply.