My van's check engine light came on several months ago it comes on and off
and on and off, it was put on the computer and nothing referring to the
engine came up.  The control arm was damaged 11 years ago and I scotched
taped it.  It seemed to be fine all these years. Last year when the van would
automatically shift from 1st to 2nd there would be a rather noticeable hard
shift, that was never there before.  When I took it to the engine experts
they said its fine.  When we put van on the computer it came up that the
control arm was bad, and driving it now if I put it in drive, it is usually
in 2nd and I have to put it up one to drive.  Half of the lights in the
speedometer work when they want, my steering wheel seems to have had broken
bearings in it and it sorta rocks back and forth; loose, and my air bag light
has been on for a couple years now.  It seems that sense the computer reading
didn't suggest any engine trouble that the check engine light and others
would indicate an electrical problem.  and of course no one wants to take
apart a E150 Ford dashboard....  
I have 2 batteries in my van, the main one which is top of the line, gel
battery and the deep cycle battery, I have a new alternator, a new starter
which were installed about a year ago.  My head lights turn on, my interior
lights turn on, my refrigerator was left on by accident and my deep cycle is
dead.  When I turn my key the needle on the battery goes to about 12, but no
sound at all, not turning over, or  even trying to turn over.  Just dead.  I
would think the battery was dead but my lights, electric locks and all still
work at full power.  So  if it is not the main battery, starter, alternator...
what do I look at now?  My cap and rotor, plugs I think were done possibly 6
years ago.  Any ideas out there please?