My experience
The needle bouncing when my blinkers were on, or while putting a load such as a window or power lock on, was fixed by cleaning up the ground from the battery to the body.
The speedo going out when it was wet, was cured by cleaning up the plug, filling the connection with dielectric grease, and sealing the wires into the plug.

So far, my speedo is rock steady,.

Cleaning up the ground from the external regulator helped with the lights pulsing, FYI

Good luck

 

Yeah, mine's running great now too. Its like everyone has different issues from everyone I have talked to, everyone told me VSS, but that wasn't the problem. Just got figure it out. But like I said, mine's running good now. Hope this helps anyone else who is having problems with the ol' speedo.