Dielectric Grease

Tech Question


Eric Hufstedler, Pasadena, CA , 1974 Plymouth Valiant 318

Is using a dielectric grease (an insulator…) on electricalconnetcors a bad thing in any way? For example, could it ever prevent aconnection by not getting out of the way of the contact area?

On a similar note, I just bought an ignition switch, and all the terminalsand “rivets” are nicely crimped. Should I touch them up with solder?

Thanks! , Eric



Grease on electrical connectors is an excellent idea, in fact, it’s one thefactory went to in the mid-’70s – in a big way – as a method of improvingreliabiity (greatly reduced oxidation) before they finally went to O-ringsealed connectors. If there’s not enough contact pressure, the connectionwill fail, with or without grease.

Silicone grease is best (no water solubility), but even Vaseline is betterthan nothing. The factory used what appeared to be the cheapest grade ofpetroleum-based brown “cup grease”.

On the ignition switch, the solder is probably OK, but, overall, I think I’dadvise against it for a few reasons:

  • On your intergral-harness ’70-up switch, you’ll certainly loosen the crimpbetween the lugs and the vinyl wire insulation.
  • You may cook the grease off the wiper contacts.
  • If the plastic insulator isn’t the OEM high-temp bakelite, you may loosenthe terminals in the housing.


Dielectric greaseElectrical