Approximately 8/22/03 19:19, Bloke uttered for posterity:
A ground connection is a wire or wire braid that goes to the car body. There may also be a bunch of these tied together at the negative [black] terminal at your battery.
Basically cleaning is mechanical. Unbolt, unscrew, etc. the connection and then clean it with a wire brush, fine sandpaper, etc. until you see nothing but shiny bare metal.
Then put it back together and make sure the connection is mechanically tight.
Don't be surprised if the bad ground is someplace obscure like a mystery wire from a rear light bulb or such.
A wiring diagram sometimes helps, by looking for symptoms that have a common ground point.
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