So I finished up splicing in a new ground wire from #3 on my cluster.
I put a female spade connector on the other end and plugged it into a spare terminal on one of the circular ground rings above the fusebox.

Plugged the cluster back in and fired up the van.

No change!!!
Same exact symptoms.

So frustrating!

Do you think that finding a cluster from an actual '86 van would make any difference?
...both the ones I've been trying are from '85's.