Speedometer non-working, every other instrument working

Hello, I have a 1998 Mustang Cobra, five speed manual.
I cannot figure this out and I am starting to go crazy. So hopefully someone can help me figure this out.

So here it is!

The speedometer started to fluctuate. It would go from zero to eighty, and every now and then it would stabilize. Sometimes it would work when it was raining.
Now however, it is always at zero. All the other instruments work, everything except the speedometer. The cruise control works as well.

Now here is all the things I checked/ looked at to help narrow down the list:

1. I replaced the old VSS and checked the gear inside of the trans and that is fine as well. (New VSS + internal gear good)
2. Checked the terminal/plug in for the VSS. I cleaned the plug the best I could. Re-plugged in.
3. Checked all fuses and all are good.
4. I cleaned all the grounds I could see. Cleaned and tightened back down.
5. Took out the instrument cluster. Unplugged, looked for corrosion, looked good. Plugged back in, reinstalled.

None of that fixed it.
So, I really am lost for ideas of what it could be. Someone give me an idea of what it could be.

Thanks for your help.