Hi,
I have a 2001 Explorer Sport (build date is 3/2000). Three times I had it in 4wd hi, it switched to 2wd all by itself. And once it went back and forth a few times! I noticed the last two times I could hear the relays clicking--the exact same noise they make when I manually move the switch from one selection to the other. I definitely heard it the time it went back and forth a few times. And, the corresponding lights are going on/off (4wd hi light goes off, and the 2wd light comes on when it switches by itself from 4wd hi to 2wd). It was as if a ghost was moving the switch (but the switch is not moving).
When it goes into 2wd and stays there, I can move the switch to 2wd and then back to 4wd hi. The relay clicks & 4wd hi lights up.
It doesn't do it all the time--very intermittent. I checked my manual & I don't think there's any kind of sensor(s) that would tell the controller to pull it out of 4wd hi. I think once it's engaged, it's supposed to stay that way until I switch it back to 2wd.
So...is it the switch, a short, or the controller (the manual calls it the control module), or...? If anyone has had this problem & had it fixed, please let me know.
Thanks much for any help!!
Jim