> Still no flashing dash turn signal LED.
>
> Should I next be looking for a failed 12v source?

I'd just keep going up the line till the break in the circuit shows
up, starting with the blue ribbon circuit between the LED and the
connector. Test the two little LED sockets, one for voltage, the other
for that intermittent ground continuity. I don't have any of my
clusters in front of me, so I don't remember if the resistor sits on
the power side or the ground side of the LED. If it's on the ground
side (and I have a strong recolection that it is), you should see the
ohm meter alternate between infinity and 460 ohms (as I recall).
Voltage side should show 12v. If those are OK, then either the LED is
bad, or in backwards!

--
John Bange
'90 Vanagon - "Geldsauger"