1985 C20 Cluster Problems

[BowTies&Bugs]

I have been a long time reader but this is my first time posting.

I recently acquired a 1985 C20 LWB truck after wanting one for a long time. My hopes are to clean it up enough to make it my daily driver. I got the truck running and driving but have gotten hung up on some electrical issues. I have tried everything I know to no avail. I was hoping someone would be able to give me some advise.

Except for the turn signal indicators, none of the lights in the cluster work. All of the bulbs look fine. I pulled the cluster to see if the problem was obvious. The main connector seemed to be seated fine but there was a stray wire that was not connected to anything. I took a picture and attached it below. Could this be the ground? If so, where does it connect?

Also, this is probably not an electrical issue but the speedometer is not working. After I pulled the cluster out, I drove the truck to see if the inner shaft of the cable turned. It seemed like it did not turn even when I was going fast. Is it common for speedo cables to go bad? Or, is my problem lurking in the transmission?

Thank you in advance for the response! I look forward to getting this truck back on the road.

-Drew