Use a clean cloth dampened with isopropyl alcohol to wipe down the connector, followed by a thin application of dielectric grease. This non-conductive lubricant displaces moisture, inhibits future corrosion, and ensures a secure connection. Disconnect connector, 2. Blow out debris with compressed air, 4. Reconnect and test Before you dive into cleaning car electrical connectors, a. On connector surfaces, dirt, dust, and other pollutants can build up and result in poor connectivity or even damage. You'll feel empowered to tackle this task on your own, saving both time and money. Wipe around the ferrule twice using lens paper soaked in 99% isopropyl alcohol.