RE: 89 200TQ Fuse Blown

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

> >Do you have the cigarette lighter installed in the rear? Has anyone been
> >using it lately?
> >
> >Recently I encountered fuse #4 blowing while I tried to re-establish the
> >function of the rear-seat cigarette lighter (rear center console). Once I
> >reconnected the lighter's power (it was disabled by the PO) I discovered
> >that there was a short circuit in the lighter(which appears improbable,
> but
> >it did indeed blow that fuse.)
> 
> i had this problem after my son put a dime in the rear cig lighter.
> i also can't imagine how it can short internally, but it is indeed
> shorted.
> 
... I don't know how much technological improvement there has been in
cigarette lighters since the early '80s, but having dealt with the cigarette
lighter on the QTC I can tell you without doubt that it really isn't
difficult at all for an internal short to occur in the lighter socket.  The
socket consists of a couple pieces of plastic and the sleeve and center
contact.  If the metal pieces do not remain correctly indexed into their
locations they can rotate to the point where the hot and ground contacts
touch.  

While I do not believe it to be the problem in the instance that we are
discussing, the other thing to beware of is the fact that the rear seat
cigarette lighter power on the 5000, 100, 200, V8 and probably others comes
via the switch in the driver's armrest that disables the rear power window
switches.  As many of us know, the wiring loom that passes through the
driver's door on these cars is prone to damage from the normal opening and
closing of the driver's door over the years.  As the insulation on these
wires (and eventually the wires themselves) breaks, many different modes of
interesting behavior can develop ...

HTH!
Steve Buchholz
San Jose, CA (USA)