[s-cars] Headlight Levelling Motors

[Igor Kessel]

Bob Rossato wrote:
> The leveling motors are stepper motors, I believe.  From what I recall when
> I installed these on my Corrado, the switch will have one output for each
> motor, not an individual one for up and down as you listed.  Also, at least
> on the factory VW wiring, the switch is wired to the low beams so that you
> can not adjust them when the high beams are on.  But you could do it any way
> you like.
> 
> The headlight motor used on the Audi C4 chassis is the same one I have on
> the Corrado (actually a Passat p/n).  At the motor end you would have, 12V
> power, ground, and the control wire from the switch.
> 
> At least that's my recollection from 7 years ago, so I would get a
> confirmation from somebody else before unconditionally trusting my info.  I
> believe Igor went through this a lot more recently - as in a few months
> ago - and I'm sure his memory is a lot better/fresher.

That's correct, Bob. Besides, I always make write-ups of what I do for 
my own archive.
:)

In a nutshell:

The switch (E102) is essentially a fancy rheostat (a variable resistor).
One end (3/56b) (YEL) sees +12v off the Low/High Beam position of the 
lights switch (E1, E4)
The other end (2/31)(BRN/YEL) is grounded internally through (6/31).
The slider (4/G) (BRN/RED)goes to the relevant controlling pins of the 
adjuster motors.
The indicator lamp (L54) sees +12v at the pin (5/15a) (BLK/BLU) off the 
Fuse S14 (15A) when the Ignition is ON.
The Indicator Lamp (L54) is grounded at the pin (6/31) (BRN) and is 
internally connected to (2/31), so you may ground either one of those.

The motors (V48, V49) are indeed stepper motors.
One end on both (1/+) (YEL) sees +12v off the "Low/High" beam position 
of the lights switch (E1, E4)
Both opposite ends (3/-) (BRN/YEL) are grounded at the switch (E102), 
but may very well be grounded elsewhere. I guess it was a safety 
measure, should one decide to remove the switch, the motors lose 
continuity and do not make funny noises trying in vain to position 
themselves home like mine did, before I found out this peculiarity.
The controlling pin (2/G) (BRN/RED) on both goes to the switch (E102).

The schematic can be found here, illustration 11/4
http://www.isham-research.com/quattro/wiring/TypC4/audi_100_sw_gasentladungslampe_mj1997.pdf

-- 
Igor Kessel
two turbo quattros