Hi US Diver,

I think it's likely that the two issues are unrelated.
Maybe the sensor is OK back at the rear end differential.
You have a good chance of finding the problem by removing the instrument cluster.

4 pin connector D in the center of the cluster is for the speedo/odo.

First make sure Connector D is seated and making good connections from the connector wires to the onboard tracks with your ohmmeter.

There's an unspecified series component in the speed sensor circuit. One end tied to connector D2, surely a capacitor that may have failed open or short, or have a bad solder joint. There's no component value in the manual.

You can measure with an ohmmeter: D2 (Br-white wire) to ground
found at pin 2, at 8-pin Connector A (upper left connector looking from back)
The wire at pin 2 is Br-Gr.

Also verify the tracks of the flex card from D1 and D2 to the speedo S- and S+ connections. Bad solder connections are common on the flex card
requiring careful solder re-flow and if the bad joint is where the track goes to the other side of the flex card and back, you need to add a jumper.
There are dotted lines printed on the flex card to highlight where the jumper needs to be placed.

Give an email address and I'll send you the wiring info for the Speedo and instrument cluster that makes it easier to understand the above.

Good luck, Bill