How do you test a headlight switch for a 1989 200TQ Sedan?

[Ed Kellock]

It looks like 30 (R 2.5) goes to 12v and tees with 30 on the flash/dim
switch.
X (BK/Y 2.5) gets triggered by the ignition switch.
56b (Y 2.5) on the flash/dim switch supplies power to the left and
right low beam fuses.
56a (W/BK 2.5) on the flash/dim switch supplies power to both high
beam fuses.

You might actually have a problem with the flash/dim switch.  Power
from the main headlight switch goes through the flash/dim switch.
With the headlight switch on, you could try to put 12v to 56a or 56b
on the flash/dim switch to see if you get lights.

Ed

----- Original Message ----- 
From: "Dave Haupt" <quattrodave at yahoo.com>
To: <quattro at audifans.com>
Sent: Saturday, May 07, 2005 8:17 PM
Subject: How do you test a headlight switch for a 1989 200TQ Sedan?


> My headlights just died one day, not so long ago.
> Unfortunately, it was while on a 650 mile drive from
> my old home to the temporary "corporate housing" which
> I will inhabit for some months, while the Bentley is
> held hostage in storage possibly hundreds of miles
> away.
>
> I replaced the headlight switch, since that's been the
> culprit in the past, but the headlights still don't
> work!  So I took a DVM to the old headlight switch,
> and have not found any contacts that get made when the
> switch is moved to the "headlights on" position.  Can
> the old switch and the new switch both be bad?
>
> The high/low for each side are separately fused - and
> the four fuses are all good.
>
> More detailed description of symptom:
>
> Headlight switch to first position, and the parking
> lights come on as normal.  Move headlight switch to
> second position, and I don't get any headlights, and
> the "bulb dead" alarm goes off.  Whether the headlight
> switch is "on" "park" or "off", if I pull back on the
> stalk for highbeams, I get the blue indicator on the
> dashboard that the highbeams are on, but they don't
> actually come on.  This is the identical set of
> symptoms as I had last time the headlight switch
> failed.
>
> What would be ideal is if someone could tell me which
> pins on the switch ran to 12V, and which ones fed the
> low, and which ones fed the highbeams.  They all have
> labels, little letters, maybe they're shown in the
> Bentley.
>
> The vehicle is a 1989 200 Turbo Quattro Sedan, very
> early version, built about June/July 1988 with the
> single knock sensor MC 10V engine.
>
> My night time driving is dependent on some clever BTDT
> from this educated group!
>
> Kindly,
>
> Dave H
> Somewhere between Santa Rosa, California and
> Beaverton, Oregon
>
>
>
> Yahoo! Mail
> Stay connected, organized, and protected. Take the tour:
> http://tour.mail.yahoo.com/mailtour.html
>
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