1995 Honda Civic speedometer is not working

Check the fuse. If the fuse is fine, unplug the VSS harness clip.

You should have 5V at one wire, ground on the next wire and the other wire should have nothing. If that checks out, plug the the connector back in, backprobe the wire the had no power or ground (that is your signal wire). Jack the front of the vehicle up and spin the wires, you should see some voltage coming from that wire. If you do not see voltage, replace the sensor