Dielectric grease.
As long as you have clean metal, the grease will not inhibit the connection, but will seal it from outside intrusion, corrosion and potential wet condition arcing.

I like the Motorcraft version, but pretty sure they are all about the same.

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On some nights I still believe that a car with the fuel gauge on empty can run about fifty more miles if you have the right music very loud on the radio. - HST

1983 300SD - 305000
1984 Toyota Landcruiser - 190000
1994 GMC Jimmy - 203000

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