I have a 2000 Expedition, 75K miles. On 1/1/04, I was on a very slushy road. The slush would come up over the hood on my windshield. The next day, I went to start the vehicle and when I went into drive the radio and clock stopped working and my 4X4 would not work. When I put it in park everything reset and came on. Later that day I had to run to the airport. The same thing happened only while driving the wipers stopped working, the windows stopped working and my dome lights would not work, on top of the radfio and 4X4 not working. I pulled over put it in park that reset everything (as soon as I went into drive the radio and 4X4 would stop working). I brought it into the shop on 1/6, they said they couldn't make the problems re-occur (the problems had gone away). I told them that I new there was a control module under the dash and one of my friens Expeditions had a water leak that caused the same problems. They are repalcing the module now and looking for the water intrusion point.
