2006 5.4 xlt not going into four wheel drive
 

I have a 2006 5.4L 4x4 f150 in which the four wheel drive is not working correctly. When i switch the dial to 4 high it fails to engage. The lights on the dash do come on but I am wondering if anyone has any suggestions as to where to start with this issue. I'm having the same issue with 4 low. I have been able to get it in 4 hi by driving in reverse, but this does not even seem to work at all times. With there being already over a foot of snow on the ground i need to get this figured out. Any suggestions would be much appreciated!

It may be problems with the vacuum lines going into your front hubs. You might want to check and see if they are still attached, or have holes or abrasions in them. That's a good place to start.

Okay thanks I'll check into that. I've also heard about a small motor on the tcase that gets corroded. Have you had any experience with that?

Fortunately I haven't. I got my truck from Texas, and hasn't been driven in the harsh Michigan winters here since I brought it up here, so I don't have many corrosion issues. However, if you are in a spot that uses a lot of salt for road conditioning, it can always be a possibility.