Hi Volks -  I have recently upgraded my leaking, corroded 82 diesel radiator
to the later model (an 86).  The majority of all that has worked out very
well, in that there are no leaks and the coolant heats up quickly and stays
on the LED like it was nailed there.  That's the good parts.  When I turn
the key the LED blinks the 5 times like always, but since this changeout
which includes the newer 3-wire aux fan temp sensor, it also goes through
this routine when I turn the key further after the glow plug light has gone
out, as I start the engine.

The installed sensor is used and I did not check it before installation.  I
did check the fan (reused my old one) by shorting two of the wires.  Looking
back, the sensor is for the 86, where the radiator came from and is a few
degrees off of that the diesel version is spec'd for.  Since filling the
system with distilled water and radiator flush, it's been working so well
that the temp has never risen above the LED so its never been hot enough for
the fan to kick in, so I have no knowledge if the sensor is working.  We
are, after all, our own worst enemies, are we not?

My question is this:  Is the "double" blinking light sequence just a random
issue or is this some arcane VW warning that is not published?

yours truly,

--
Alan Felder
Austin TX
82 Diesel Westy