weird fog light problem

[Huw Powell]

Dan Simoes wrote:
> 
> Good idea, but that's the odd part.  The switch itself has 12v going
> into it, and has two outputs, both supplying 12v each.
> Somewhere, there is a drain bringing it down to 6v, but I can't figure
> out where.  I'll have to look at Bentley again.

At least you have the Bentley, I'm working "blind"!

The rear fog switch has *four* terminals that are combined when it is
on.  One would be power in.  One would be power to the rear foglight. 
One would be power to the front fogs, and the last one seems to turn its
indicator light on (the big arrow).

I suspect a poor closure of the switch inside with enough internal
resistance to create your voltage drop, and still say you should clean
the heck out of it.  You could always try measuring the resistance
between the various terminals.  i wish I could remember the terminal
numbers from when i was doing it.  i wish I had your Bentley...

> 
> Huw Powell wrote:
> >
> > you might try giving the inner guts of the rear foglight switch a good
> > cleaning.  That has been essential to getting full functionality out of
> > the dash switches in my 90.  clean the slider contacts, and spray
> > cleaner into the inner sanctum where I suspect the actual "switch" is
> > hidden away.
> >
> > Dan Simoes wrote:
> > >
> > > Here's an odd one.
> > >
> > > Background:
> > > On the 1990 90q 20v I just recently purchased (yes, I'm already working
> > > on it!), the front fogs are missing.  I took out most of the dash
> > > switches to replace bulbs, and in doing so noticed that there was a cut
> > > wire behind the rear fog light switch.  I fixed this with a buttsplice
> > > connector (which I rarely use) and it seems fine, has 12v on both sides
> > > of the wire.
> > >
> > > Ok.  Now, symptom.
> > >
> > > With the front fog light switch on, there is 12v at the front fogs, as
> > > there should be.  When I use the rear fog light switch, the rear fog
> > > lights up, and the fronts are only getting about 6v, which begins to
> > > drop if I leave the switch on.
> > >
> > > There must be a current drain somewhere, but I can't guess where.
> > > Bentley shows that the rear fog switch energizes the same wires as the
> > > front fog switch would, in getting juice to the lights.
> > >
> > > Anyone BTDT?  Just wondering.
> > >
> > > Thanks.
> > >
> > > | Dan |
> >
> > --
> > Huw Powell
> >
> > http://www.humanspeakers.com
> >
> > http://www.humanthoughts.org

-- 
Huw Powell

http://www.humanspeakers.com

http://www.humanthoughts.org