I am having a problem w/the 4X4 system on my 2000 Expedition. It will go into 4wd by itself sometimes after being stopped for a brief time such as idling at the espresso stand or starting it after getting gas. Then it won't come out without monkeying with the switch, backing up, shutting it off again etc... It once even went into 4wd lo when the switch was still on automatic. Other times after using 4WD for a short amount of time, it won't go into 4WD. I have had the GEM check for any codes that might have been set, there were none. I spoke with a friend of mine that works in the parts department of a dealership, he said they have never stocked or even sold the switch that goes in the dash, that tells me that it is not a common problem. The vehicle is out of warranty, although I did have this problem checked before it went out of warranty. Of course they couldn't find anything either. Any info would be appreciated

 

If it's happening often, this is what I would do. I'd disconnect the hot wires from the switch and see if it still happens. If it stops, then it's probably the switch.