Chevrolet Repair: 1990 Chevy Truck Speedometer, vehicle speed sensor, automatic overdrive

Question
I recently purchased a 1990 C1500 Chevy Pickup. The speedometer didn't work when I purchased it. The wires to the vehicle speed sensor were cut. I replaced the vss and put connectors on the wires. I have swapped the wires both ways because I was not sure which one went where. I have checked the fuses and disconnected the battery cable to clear the trouble codes. My speedometer still does not work. I am not sure where to go from here. I cannot find any information on how to approach the dash unit. The truck is a 1990 C1500 5.7 engine code K the trans is a 700R4 I believe. It is an automatic overdrive. Any help would be greatly appreciated. Thank You

Answer
To properly test the speedometer you need to have a scanner and a speedometer test.

Is the ECM setting a VSS code? If yes then it's most likely a defective VSS, (you stated that you already replaced that)
or the circuit from the VSS may be open somewhere.

Checked the voltage output from the VSS.
Test the VSS circuits from the sensor to cluster & ECM.

You can go to eautorepair.net and get the diagnosis and repair info from the service manual for $9.