quattro digest, Vol 1 #4307 - 13 msgs

QSHIPQ at aol.com QSHIPQ at aol.com
Sat Dec 7 14:12:44 EST 2002

[ Picked text/plain from multipart/alternative ]
Well, let's understand how that works first.  The rear locker is identical in
design and execution as your 4kq.  As of 1988> the rear locker used an
electronic box to engage the rear diff, giving you a push button instead of a
vacuum knob.  When they did this, they also added a ground wire to the
controller that is triggered by the ecu speed sensor output.  At 15mph, the
ecu sends a ground signal via the controller blue/white wire, which cancells
the vacuum solenoid that has locked the rear diff, which then allows vacuum
to the open side of the actuator, unlocking the diff.

Without the ground signal interrupt from the blue/white wire, the rear locker
will stay locked until the driver pushes the switch again.

I know it works this way, and you can convert your 4kq to be electronically
locking, since I did this mod on my 83 urq with lockers.  I haven't hooked up
the blue/white tail to anything yet.  For the detailed look of this
conversion, ck out:


Hope this clarifies things a bit

Scott Justusson

In a message dated 12/7/02 11:08:44 AM Central Standard Time,
quattro-request at audifans.com writes:

  Yes, I can certainly understand that now; having only owned 4kq's I'd no
idea that the lockers in the later cars unlock without driver intervention.
I think that might make me mad :)


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