2002 EB V8 Explorer

Today was the first snow storm of the year. I got out of work and
hopped in and started heading for home, but I quickly found that four
wheel drive was going to be a necessity. I hit the 4X4 High, but
nothing happened. No light came on on the control panel, and I
definitely did not have four wheel. I tried putting it in Neutral and
tried 4X4 Low: same thing.

Here's the deal: I have posted my other electrical problems to this
forum in the past (only one reply came from someone who replaced a
wiring harness for his fix) without any insight forthcoming. I am
thinking there is a connection between all of my problems; perhaps
someone can help to make that conection for me.

1. No 4X4
2. When I turn on Rear Defrost I get a warning that a door is ajar,
and the interior lights come on
3. I cannot use the electric toggle switch for the door locks on my
driver door unless the car is running (or key turned to 'on');
passenger side works fine.
4. The radio and accessories now only work if it is running, or the
key is in 'on' position

I would like to avoid taking it in to have someone rack up hours
diagnosing an electrical problem if there is someone on the forum who
can point me in the right direction to start looking. The snow is
still falling...