Hello Roadsters, I have a Ron Francis Roadster harnes. I have a 200MPH Autometer Speed gauge. I have a electric 2-wire sending unit. I believe I have everything connected correctly. I was a little fuzzy with the 2nd gray wire that goes to the ground.

1. Green Wire to Sending Unit
2. Gray Wire to Sending Unit

3. 2nd Gray Wire to a ground?

Any help would be appreciated.