Dielectric grease is a silicone-based, non-conductive grease that seals electrical connections against moisture, road salt, and corrosion. A dab on a spark plug boot, battery terminal, bulb socket, or wiring connector keeps electricity flowing where it should — and keeps corrosion from ever starting.
What Does Dielectric Grease Do?
Because it's an insulator, dielectric grease doesn't conduct electricity — it surrounds the metal contact area and blocks out water and oxygen. The metal-to-metal contact still carries the current; the grease seals everything around it. The result: no green crust on battery terminals, no corroded bulb sockets, and spark plug boots that slide off easily at the next tune-up.
Choosing the Right AGS Dielectric Grease
- Connector Protector® – the all-purpose choice for trailer plugs, wiring harnesses & outdoor connections, in 4 oz tubes or single-use pouches
- Dielectric Silicone Grease – 1.25 oz & 4 oz tubes for the toolbox
- Dielectric Bulb Grease – single-use pouches sized for headlight & tail light bulb changes
- Battery Terminal Protector – formulated for battery posts & clamps
- Sil-Glyde® Boot Protector – for spark plug boots & ignition components
Where to Use Dielectric Grease
- Spark plug boots – prevents boots from bonding to the plug and stops voltage leaks
- Battery terminals – blocks the acid corrosion that causes hard starts
- Bulb sockets – headlights, tail lights & marker lights stay corrosion-free
- Trailer & wiring connectors – essential for any connection exposed to weather
- Weatherpack & sensor connectors – keeps moisture out of low-voltage signal circuits
How to Apply Dielectric Grease
- Disconnect the connector or pull the boot, and make sure the contacts are clean and dry.
- Apply a thin film to the inside of the boot, the rubber seal, or the connector housing — a little goes a long way.
- Reconnect firmly. On tight automotive connectors the metal pins wipe through the grease and make solid contact while the grease seals out moisture around them.
- Wipe away any excess so it doesn't attract dirt, and reapply any time the connection is opened.
Dielectric Grease FAQ
Is dielectric grease conductive?
No — dielectric means insulating. It should be applied around and over connections to seal them, and it will not create a short between adjacent terminals.
Should I put dielectric grease directly on the metal contacts?
On tight-fitting automotive connectors, yes — the mating surfaces wipe the grease aside and make solid metal contact while the grease seals the rest. For high-resistance or low-pressure contacts, apply around the connection instead.
Is dielectric grease the same as regular silicone grease?
They're closely related — dielectric grease is a high-purity silicone grease rated for electrical use. Regular petroleum-based greases should never be used on electrical connections or rubber boots, as they can degrade insulation and swell rubber.
How often should I reapply?
Dielectric grease doesn't dry out or wash off in normal service. Reapply whenever a connection is opened — at bulb changes, battery replacement, or tune-ups.
