Window Relay Clicking '92 100

[Scott Mockry]

Frank,

I ran across this same problem  on a friend/customers 1992 Audi S4. He
would come back to the car to find all the windows and sunroof had closed
on their own, and at some times, their was a strange, loud clicking sound
coming from the bank of relays in the drivers side kick panel under the
dash. The battery would be quickly drained from this fun little exercise
and the relays behind the kick panel would get very hot.  Trying to predict
"when" this relay clicking problem would occur was not very straight-forward.

Here is what I found out by spending a day trouble-shooting this car...... :-(

The central locking/Alarm system/Interior light Delay Control Module (V94)
which is all incorporated into the door lock Vacuum pump assembly under the
back seat, next to the battery,  controls this feature which allows closing
all the windows and sunroof from the front door lock/key switch. 

When the driver is locking the car door, and holds the key over to close
the windows and sunroof, there is a yellow wire at pin #8 (Designated T16/8
in the wiring diagram)  on this (V94) central locking/Alarm etc. control
unit which sends a ground signal to the Power Window Control Module (J139)
on pin 10/SK to initiate closing all the windows and sunroof  via  the
Automatic Window Closing Relay (J261) (short stubby 50A relay). The (J262)
relay is activated by pin 6/KR from the (J139) window control module.

 As you know the (J139) control module and the (J261) relay are located
behind the left kick panel cover, drivers side. 

If the car battery voltage drops a little below normal,  the voltage on
this yellow wire T16/8 would also  drop down towards 9-10 volts, and at
some voltage near 10 volts, the Power Window Control Module (J139) would
begin to oscillate and rapidly turn the Window Closing relay (J261) on and
off in a most bizarre fashion. I was able to duplicate the problem
repeatedly by using some 5-10K ohm resistors to load down the voltage on
this yellow wire T16/8 until the problem would begin to occur. 

On my friends '92 S4 car, the aftermarket radio had been installed
incorrectly, and was draining the battery down slowly over time. Keeping
the battery charged at the normal voltage "seemed" to eliminate this
problem from occurring.

Disconnecting this T16/8 yellow wire from between the (V94) Central
lock/Alarm unit and the Window Closing Unit (J139) will also prevent this
problem from occurring, and you only lose the window/sunroof closing
feature using the door key. The windows and sunroof work normally from
inside the car.

I suspect there is a problem with either the drive circuit in the (V94)
central locking control module, or more likely a problem with the logic
circuit inside the (J139) Window Control Module which causes this odd
behavior when the drive voltage is somewhere near 9-10 volts, in-between
+12V and ground potential. Whether it is a design problem, or a failure of
some component inside the (V94) Control unit or (J139) Window closing unit
is unknown to me. 

My friend did not want to fork out the cash to buy a new V94 Central
Locking/Alarm etc. unit, or to try buying a new Power window control (J139)
to see if this would completely eliminate the problem, so we just left the
Yellow wire disconnected. He talked to another Audi 100 owner, who had his
car at the dealer with this same problem, they replaced  the (J139) module
and the (J261) relay but this did not appear to solve the problem.

HTH
Scott


>Frank said:
>I've had the same problem in my 92 100.
>I didn't give it much concern until  my battery
>kept going dead and my windows started to 
>go up while the car was sitting parked.
>For a quick fix, I ended up pulling out the $300
>control relay and wiring a separate relay in its 
>place to operate the windows. Doing that, you loose 
>the express down feature on the drivers window and also
>the locking feature that makes all of the windows and 
>sunroof close when you lock the car with the key.
<SNIP>