The turn signal indicator is not connected to the instrument cluster
ground. It does not use that ground. It can still be affected by that
ground but only indirectly.

The blinking temp led issues have various elements that can be the root
cause of spurious blinking. More than one problem can exist with this
circuit on the same van.

The coolant level warning relay '43' output signal connects directly to
the temp gauge wire that controls the temp needle.

More than one problem can exist in the dash/IC. Just because a step does
not seem to fix anything or everything does not mean the step was of no
value. Some steps are intended to reduce the number of other
possibilities as much as they are the fix things.

I'm sure that you think just the opposite but the new turn signal led
behavior since you strengthened the cluster ground in fact points to
where the real fault likely is.

Mark

Jim Felder wrote:
> Three-year-long story short: No turn signal indication on the dash,
> other than the relay clicking. Over this winter, on cold days, temp
> needle went nuts and temp LED flashed until car was warmed up.
>
> Replace the temp "relay" and the temp needle calmed down for good, it
> always operates properly now--which is strange, because I wam told
> that the relay controls the light, not the needle.
>
> At first the blinking light would not quit and as the car warmed up,
> this blinking because so intense that for all practical purposes the
> light was always on at normal temps.
>
> Then this quit, and my turn signal indicator light started working for
> no apparent reason as long as the headlights were off. If they were
> on, no turn signal indicator light.
>
> Sooooo, I thought to myself, "very good, better anyway, but you
> haven't done anything to improve the grounds.
>
> So I did as Mark D. and other suggested and cut the two brown wires to
> the big connector and soldered them to a big common ground wire with a
> ring, and put that under the big screw supporting the heater lever
> assembly. I soldered the two "tail" ends together.
>
> Now I get this: no turn signal indication under any circumstances, and
> the temp LED blinks unless I cycle the key on and off a few times to
> kill it.
>
> Jim
>