there are a couple ways to "clean" those connections, the fix it and
forget it ways are these.  make yourself a little tool to disengage the
spring clips on the terminals from the plastic housing.  then cut the
crimp terminals off and crimp on some new open barrel terminals.  the
truth on these connectors in vanagons is that they usually fail in three
ways in my neck of the woods.  1)the plastic connector breaks  2)the
wire cooks and the shielding becomes brittle 3)the terminals corrode were
the wire is crimped into the terminal.

what i do is cut the wire back to were its supple, match the wire with
wire in my junk collection, solder length of wire on usually longer than
vw did cover with two layers of heat shrink, then crimp on new ends.  for
the plastic housing i generally source later style housings that have the
push release for the connector instead of the type that are on the
vanagon.

the much easier and less futzing around way to do things is to buy a Ford
or GM pigtail with connector at your FLAPS and connect it to your
harness whatever way you see fit.  this method costs much less both in
time and tooling since most people don't have an open barrel crimper and
access to the correct terminals.  the fact is this is now how vw sells the
stuff now, they used to sell crimp terminals but that is no longer the
case.

jonathan