What’s the Use of Dielectric Grease in Car Maintenance?

QuestionsCategory: Ask An ExpertWhat’s the Use of Dielectric Grease in Car Maintenance?
Joseph Smith asked 5 months ago
Hi, I'm planning to replace my alternator and I've heard about using dielectric grease on the new alternator's connections. I'm a bit confused about the properties of dielectric grease. I've learned that it doesn't conduct electricity, but rather prevents it. Why is it then recommended for use on battery posts? Won't it hinder the electrical connection? I'm trying to ensure I use it correctly to prevent corrosion without compromising the connection's effectiveness. So, what gives?
1 Answers
Zack Norman Staff answered 5 months ago
Hi there, Joseph! Your question about dielectric grease is a great one, as it's a common area of confusion - even some pros and mechanics still debate its proper uses and when's best to actually apply them. Firstly, you're correct in understanding that dielectric grease is non-conductive. It's designed to prevent electrical connections from corrosion and moisture, not to facilitate electrical conduction.
  1. Using on Alternator Connections: For your alternator replacement, applying a thin layer of dielectric grease can be beneficial. It'll help prevent corrosion and ensure a long-lasting connection. However, be cautious not to overapply, as it can become counterproductive.
  2. Dielectric Grease Properties: It's true that dielectric grease doesn't conduct electricity. Its primary role is to seal out moisture and protect electrical connections from corrosion.
  3. Application on Battery Posts: Regarding its use on battery posts, the grease acts as a barrier against corrosive elements. When you apply it and then connect the battery terminals, the pressure displaces the grease at the point of contact, ensuring a solid electrical connection while the surrounding areas remain protected.
  4. General Advice:
    • Use it sparingly; a little goes a long way.
    • Apply it on the exterior parts of connections, like the outside of battery terminals or bulb sockets.
    • Avoid using it on parts where electrical contact is critical and where it might impede the connection.
Remember, the main purpose of dielectric grease is protective, not conductive. It's a useful tool in your automotive maintenance kit but should be used judiciously. Hope this clears up your confusion! Zack - Motor Verso Mechanics Team