I have an 84 733i, and I've been working on fixing several of the
problems in the car.  One of the last ones that immediately concern me is
the temperature gauge, which doesn't budge.  The sender is good, the
indicator is good (passed some current through it,) and I can "see" the
sender from the connector going to the instrument panel, so there is a loss
of the signal inside the panel.  The wiring diagram shows a component in
between the connector and the indicator, (forgot exactly what it was called,
and the book is out in the car right now) so I would like to check that out.
I assume that it's the chip where the signal is disappearing, and was
wondering if by chance a reset might correct the situation.
   Which leads me to ask: what exactly is the reset tool mentioned in the
books, and how is it used?