Hi guy,

Did you see my post with the link to getting the wiring diagrams for the '87 model? It is close enough to to work for your car.
If you can get to around page 58 you can see how the cluster gets power. The red lines will show how it comes from the ignition switch and to the clip on the speedometer Art mentions. The red arrows show the direction of current flow with the engine not running.

There is a tiny squiggle right at that point that touch onto the voltage regulator "M." It is my guess that that squiggle in the tiny box might be the clusters personal fuse. So you can see where Art points to why the gauges are not working.
The best way to learn how to read schematics or diagrams is to have a need to know and a fix happens. You'll get that feeling that you won the lottery with a minimum investment.

That connector can get loose on the circuit board of the speedometer but I imagine the power takes off from there before the wire node. If only the speedometer stop reading out the speed a little thicker film of solder onto the board can restore that connection.

The fuse link that Art is talking about looks like a circuit trace film going over the top of the speedometer head. It is held down by two screws that have to be secure. It's about two to three inches long.

As Art said, there is no need to pop the steering wheel off. You just need to have wheel pointed straight ahead so the upper flat half is not blocking the cluster so you can shift it out on end enough to unplug the right hand side sockets.

Again there has to a good light bulb in the socket of the "battery light" of the cluster. The break is on the Board or the power or ground connection to the whole she-bang.

May the force of tonight's storm go around you all in the Northeast.

Phil