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Dielectric grease

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M

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Does anyone have any experience with diaelectric grease? This is a mystery substance to me... A mystery substance because half of what I read about it is contradicted by the other half of what I read about it.

It is recommended for protecting electrical connections from corrosion, and there is a YouTube video showing someone applying it to connectors. They say that it will enhance the electrical connection because it prevents corrosion and keeps out water and air.

But, it is an insulator and does not conduct electricity. Those who point this out say that it will interfere with the electrical connection and may even prevent it altogether.

So who is right?

I'm thinking that it might be ok to apply it over an electrical connection (like the screw holding the battery ground to the car) to keep out moisture, but not between the connector itself and the metal of the car. There, I would think you'd want to have metal to metal.
 
Sure, I use it frequently. The grease itself (like pretty much all grease) is non-conductive, but it's also relatively easily displaced at pressure points. Thus you wind up with metal-to-metal to do the conducting, and a protective barrier of grease around the contact point to help prevent corrosion.

BTW, Vaseline works almost as well. The "dielectric" stuff is just a little better, takes longer to dry out, resists water a little better, etc. I use Vaseline for things like taillight bulbs that I know will be replaced in a few years anyway. "White" grease works well too, if that's what you've got handy. Likely any type of grease would work (but those are what I've tried).
 
I use it on every bullet and spade connector. I even coat the terminals for my relays (headlights and driving lights). Helps to get these type connectors apart too.

Never had a conectitivy problem. I always have a large tube in the garage.

Last time I bought it one of the stores (I think carquest or NAPA) wanted a lot of $$$$ for the large tube, I think i got it at autozone for about $8
 
Thanks, I learned something as I had the same question. I was uncertain if dielectric grease actually enhanced conduction or if it was non-conductive.

Randall helped me this spring diagnose highly corroded connections on my ammeter. I was getting a huge voltage drop at my coil (causing stalling at idle) and headlight barely lit at idle.

Anyway, I pulled the gauge, cleaned all the contacts (both on gauge and wires), applied a generous coat of dielectric grease and installed new connector terminal rubber sleeves (originals had partially melted due to heat due to resistance caused by corrosion on terminals!). Reinstalled and everything now perfect. 12.5v at the battery and 11.5v at the coil. Headlights bright as ever and engine now fires instantly on first crank.

I applied the dielectric grease to prevent a future re-occurrence of this corrosion on the ammeter terminals.

Bob
 
Thanks. That helps a lot. I think I will use the dielectric grease sparingly to encapsulate the contact points to keep moisture out. I'll brush it on so it gets down into any cracks and crevices. Also, I'll put it on the screws so it forces grease into the holes where the ground cables attach.

I, too, though about using Vaseline, but the clerk at the auto store told me that dielectric grease will last longer.

I confused her a bit at first by asking for "dialectical" grease! Ha, ha!
 
LexTR3 said:
I, too, though about using Vaseline, but the clerk at the auto store told me that dielectric grease will last longer.
Click to expand...

I use store brand vaseline. I've never been able to see much of a difference between it and the grease other than cost. I've neer had it "wear out" on my, but the electrical connections on my cars have only had it 5 years or so.

I hadn't seen any other comments to the effect, but it also makes it much easier to get connections back apart again. This is mainly from corrosion inhibition, but also because it does help lubricate as well a bit.

Jody
 
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