If I'm not mistaken, many modern cars have dielectric grease on/in all connections. The grease eliminates air and water that can cause the connection to corrode (especially dissimilar metals). Given the choice of a dirty connector with dielectric grease and one that corroded, I'd use the dielectric grease. For that matter, I use dielectric grease at all connections in an attempt to put off corrosion. Nick Kemp Deer Lake Orchard