The 5 pin ECU power relay has nothing to do with the fan or AC, contrary
to various parts venders listings. The extra relay pin has to do with
the OBDI capability that VW was working to implement into the Vanagon to
comply with pending emissions regs. FI harnesses that are set up for the
5 pin relay have extra ECU wiring pins and the 5th relay pin connects to
the ECU on one of these.

The ProTraining Manual needs a supplement to cover a few such changes
made to the Digifant setup over the years.

Mark

John Meeks wrote:
> Thanks for that info Neil. I was working from the Digifant pro training
> manual. It doesn't reference that fifth pin. It looks like it triggers the
> high speed fan when AC is in use. I left the AC setup off for my post fire
> rebuild so it's kinda moot. :-)
>
...................
> On Mar 11, 2013 4:17 PM, "neil n" <musomuso@gmail.com> wrote:
>
>> Hey John.
>>
>> Though you've found out, for the rest, the power (ECU) relay has 5
>> pins after '88/89.
>>
>> I think there's a changeover in '88 as my '88 has a 4 pin relay.
>> Van-cafe shows this:
>>