Beneath ours, for other reasons, I came across three or four ground connections to the frame.
As a preventative measure, I pulled them apart, cleaned copper wire with steel wool, removed the ground clamp, cleaned where the wire goes, cleaned the mount area for the clamp, again, I use the de-ox grease on all connections remounting it.
The copper wire was solid #12, or 14 wire.
The clamp was a small aluminum square opening with a set screw and a mount bolt.
Some of the cleaning was just scraping to see a small amount of bare metal (shiny) where connections would seat.
Dab of de-ox grease at all metal contact points.
As found, they were dry connected, which is okay until corrosion does set in.
I must say, we were not experiencing any problems, I just realize it could become an issue if left alone.
So, I too, agree with the many here who say maybe a ground.
__________________
|