My 83 westy has working turn signals (and emergency flashers) but
you wouldn't know it from the LED on the instrument cluster. It
doesn't work at all with the TS or the flashers.

Here's what I can tell you in a nutshell:

The LED in question works. The resistor between the connector and the
LED works. All the foil is in good shape. This is the third
instrument cluster I've tried it on. The relay is new. The wiring--
that I can see--is in good shape.

What I can't see and what may not be in good shape is the wiring out
the bottom of the relay, into the rat's nest and then to the long
vertical connector behind the clock.

How do the turn signals actually work? I seem to remember that the
relay interrupts a ground, and there is 12v all the time to the wire
to the connector that connects with the TS LED. I don't remember what
that wire is right now, but I do remember tracing it down, checking
it out, and it works. What voltage should I be looking for where on
the wires from the relay to the connector? Is there a ground to the
relay I should be looking for?  The problem almost has to be between
the relay and long connector. But what do I know. I've been trying to
fix this, the one last thing that doesn't work on my westy, for a year.

Jim