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Re: Two Questions
In a message dated 96-12-11 03:59:51 EST, APOWELL@agcom.tamu.edu (Al Powell)
> I buried two questions in a recent post - and many of you may have
> missed them. So here they are...the car is a 1990 200.
> 1) Having installed Euro-lights on a harness with relay, I need to turn
> off the "light out" warning light on the dash. I have found two
> alternatives: a) bend over one contact on the front light relay, or
> b) pull (an unspecified) wire out of "the connector for the
> auto-check circuit." I haven't found this unit or the wire...would
> appreciate specifics from the inventor of this method.
> There was a reference to a third method (possibly from SteadiRic?)
The unit in question is located in the auxillary relay panel, under the dash.
Middle row, second from the right, looks like a standard Hella relay. It is
not. It's is a logic controller, P/N 443 919 469B, built around a single chip
(either a difference amplifier or a comparator, ULX245M - a proprietary SOB,
I failed to find it in any of my databooks). The chip listens to the current,
that flows through two very low reference resistors, comprised out of two
15mm wires no less than 1mm in dia, probably Ag (they are silver colour and
have a very low resistance). The circuit listens to the impedances of the low
beams filaments and throws a red flag (6v on terminal "K", goes to a thin
grey wire, that is connected to the kompooter) if either of two conditions
1. At least one filament is blown (R=infinity) or
2. R of one filament significantly differs from R of another one. The
kompooter buzzed on me when I installed the first 9007, while still having a
9004 in another socket. Installed the second one and the damn box shut up,
One of those days I'll finish designing the circuit, that will replicate the
same diagnostic function, only on the secondaries of the light relays (I have
allready drawn it in tango.sch, can't get around to laying it out in
tango.pcb and route it. One of those days, perhaps...).
For now I can suggest my non-destructive method. You want to shunt those
calibrated reference wires. You need to connect 56bR to 56bR1 and connect
56bL to 56bL1. To do this without damaging the original controller I took an
old (a burnt one is OK too) standard 4- or 5-pin relay and gutted it out.
Then I have soldered it's terminals in pairs so that when plugged instead the
OEM controller, it would be as if you've done the above procedure on the OEM
conteroller. Two smaller jacks in the controller socket, 31 and K, will be
unused, so that the kompooter won't see a red flag on terminal K and be
happy. ( I don't have a relay in front of me and don't want to mislead you -
you figure it out, either 85+30 and 86+87 or 85+87 and 86+30. BE CAREFUL, try
not to screw up here! Use a thick wire for soldering).
> 2) My A/C fresh air flap is not closing on ECON of DEFOG. I
> replaced the (broken) spring which should assist it to close, but
> can't find a good attachment point for the forward end of the spring.
> All I can do is run it straight UP to the servo above it, and it
> seems to lack leverage. WHERE DOES THE forward end of that
> fresh air flap spring mount? Would someone please look and tell me?
> I think you can see it from below with a flashlight without moving
> anything out of the way. It's right above the passenger's toes.
This is a very typical Audi problem (at least I saw it and repaired on 3
cars already). Usually it's not a spring.
If you remove your glove compartment and do some acrobatic, you'll see a
vacuum valve that controls the fresh air input/recirculation flap @ the AC
coil. The valve is twisted in to a plastic bracket which is a part of the
whole AC housing. The bracket usualy snaps broken, leaving the valve hanging
in the air. If it's the case, the flap goes into the default (fresh air IN).
In all three instances I was able to fabricate a rather fancy shaped
metal bracket, that snaped into place instead of the piece, broken off
those plastic dual rails. The valve went into the bracket and the flap
started working again.