That is for the indicator light for the center locking diff.  If you go to
the front of the Syncro you'll find another one there for the front locking
diff.  VW wired for them even on Syncros not equipped with them.

Brad Spear
'72 Westy
former owner of '87 Syncro GL

P.S.
Squirrels chewed through the connector to the center locking light.  Must
taste good.  I'll take their word for it.

In a message dated 29-01-2000 16:35:02 PM Central Standard Time,
bpchristensen1@HOME.COM writes:

> I'm inspecting my rear brakes and just forward of the driver's side wheel,
>  tucked in aft of the charcoal/vacuum canister is a rubber boot with a
couple
>  of connectors in it.  The boot says "Germany" on it and has a VW emblem, so
>  I'm assuming this is stock.  Anyone know what this is for?
>
>  Brent Christensen
>  '89 GL Syncro Westy "Klaus"
>  Santa Barbara, CA