Yes, VW changed this wiring over the years to make it more robust. The
83,84,85 and early 86 version used 2 smaller wires to carry all the
current from the alternator.  Late 86 and all 87 used one larger wire
and one smaller wire, then 88-on used one very large wire and one
smaller wire.

The early version is inadequate and I have seen many with signs of
melting. The later models used the 1 large wire for the charging current
and a smaller wire for powering the the fuel injection stuff. The early
version used 2 small wires in parallel to do both jobs in one.

The A/C equipped models used a separate third wire from the alternator
to the main A/C unit.

Mark

kdlewis_wasting_time@access4less.net wrote:

>Dave,
>    The wire between  the alternator and the starter needed
>upgrading in our 86 and 85. They both had an unacceptable
>voltage drop (across this wire) when all the electrical
>consumers were on. In the 85 this resulted in the battery
>getting under-charged while running the A/C.
>
>
>
>