[tinkering]

This is a late follow up but better late than never. The whole problem was attributed to the PCM and fusebox that these Expeditions etc. and F150s right up to the current years are experiencing. Water gets through the wind shield seal and into the PCM and the fusebox behind the dash. I changed them out and all of the meriad of electrical glitches were no more. I also replaced the burned out dash lights. NICE. Even the intermittent problem with the key and the security system went away.
I took it into a glass shop who knew how to seal everything up properly. VOILA!
I also applied sealer to those channels that travel along the length of ths roof. The factory sealer cracks and water seeps in there too. Ford isn't all better ideas.
The main thing though was the transfer case began to shift properly into and out of low, with the dash 'low' indicator light smiling back at me for the first time since owning it!