You reseated the 4 pin connector at the instrument cluster?

Here's a way to check the pair of grounds to the speedo/odometer:
get your ohmmeter on pins 2 and 3 of the 4 pin speedo connector at
the instrument cluster. Pin 2 has a green/black wire to ground at
a junction under the ECU AND the Brown/White wire from the speedo transmitter.
Pin 3 has a brown wire to the ground rail at the fuse block and there's another
wire from the fuse block ground rail to that same ground point under the ECU.

Measure maybe 2 ohms or less between these pins to verify the grounds.

Pin 4 at the speedo is a Blue/red wire from the ignition switch- +12VDC\

The signal wire from the speedo transmitter is a brown/white wire to pin 1
of the speedo 4-pin connector...confirm that it is NOT shorted to ground.

Post back.

Bill