C2 Bulkhead connector: apply dielectric grease or not?

[Gary B.]

Don't use "dielectric grease" on these connectors. "Dielectric" means insulator





Gary

[Edward J.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

Gary, I used dielectric grease on my 63 over 10 hrs. Ago without issues I applied to firewall connections with a acid brush.apply spareinly.

[Dan D.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

Duke is correct. Dielectric is an insulator. You are asking for trouble, regardless of what other people say.

I have not heard of using WD-40, but that probably will work. It certainly will keep water out.

I use a graphite based grease, Dow Corning Molykote G-n paste. It is a boundary lubricant containing molybdenum disulfide and other lubricants.

-Dan-

[Duke W.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

I stand by my previous recommendation on this subject - only use dielectric grease on high voltage connections, not low voltage. It's very difficult for moisture to penetrate the WD-40 film that remains after the carrier evaporates, but the film is too thin to add any meaningful resistance to the connection.

Duke

[Joe R.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

Don't use "dielectric grease" on these connectors. "Dielectric" means insulator





Gary

Hi Gary:

I share your uncertainly about using dielectric grease. It seems counter-intuitive. However, I have encountered dielectric grease on the factory connectors of modern cars using 12 V systems. The grease was on connectors that could be expected to be subjected to water spray and salt.

My sense is that people who are "connector experts" will argue that dielectric grease is not harmful to the electrical connection and is, in fact, helpful for protecting the contacts from corrosion. To better understand the rationale, the attached excerpt from a guide about connectors may be helpful (note that dielectric grease is not mentioned here).

My impression is that the A-spots squeeze out the dielectric grease enough to make electrical contact, and the dielectric grease fills the air voids to help prevent the intrusion of corrosive gases or liquids.

Given your science background in mechanical engineering, perhaps you can perform a review of the relevant literature and educate us on what you find.

I, myself, have this decision to make when I replace my forward wiring harness (some day).

[Edward J.]

[Gary B.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

Edward,

Is there a specific GM document that you can cite that talks about the use of dielectric grease?

Gary

[Gary B.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

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[Gary B.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

It’s also interesting that GM sells a product called a “dielectric lubricant”. The application description says “Used to protect electrical terminals from moisture, oxidation, and corrosion and to ease assembly of electrical connectors.” Note the lack of mention of it applying only to high voltage connections.

I don’t know how or if the GM dielectric lubricant differ from GM’s dielectric grease.

Here’s an interesting few sentences from a blog on farmandfleet,com:

”Dielectric grease can also be applied to the metal parts of virtually any electrical connection that will be exposed to the elements to serve as a sealant that protects the connection from contamination and corrosion. This should be done very carefully, as the grease will cut off the flow of electricity through the connection if some of it is left between the mating surfaces.”

Gary

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[Gary B.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

I suspect there will always be two camps on this issue, which is much more controversial than I ever expected. In any case, this person offers some interesting history. I believe the person who wrote the folliwing would be in the camp believing that dielectric grease is OK to use in most places, including the bulkhead connector.

http://www.w8ji.com/dielectric_grease_vs_conductive_grease.htm

Gary

[Phillip M.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

Gary, I use the following product which I believe fits your needs perfectly. It can also be used as an anti-seize!
Thomas & Betts "Kopr-Shield #CP16 "Connector termination Compound. Electrically Conductive, Corrosion Resistant Compound".
It contains elemental copper powder as an ingredient.
Phil M.

[Frank D.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

What "high voltage" connections are in an old Corvette - high current maybe - nominally not more than 10-15 amps I would think.
I packed my repaired bulkhead connectors liberally with dielectric...mmmm...4 years or more ago; no issues. The connection between terminals relies on direct physical contact in low voltage environments (unlike spark plugs) and so I don't see the problem. Conversely, I would be leery of a compound with copper particles swimming in it; can't say if they would make a divergent path for current flow or not but who knows.

[Gary B.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

What "high voltage" connections are in an old Corvette ...

[Phillip M.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

I have not had an incident of cross conduction with the Kopr-Shield product, but I am careful in applying it only on the contacts and not slobering it all over the place. Also, using my digital multimeter I am unable to measure any conductivity on the ohms scale by inserting the probes directly into the product. Evidently the copper loading is not high enough for electrical conduction in a free state.

[Gary B.]

Re: C2 Bulkhead connector: apply dielectric grease or not?

?..Also, using my digital multimeter I am unable to measure any conductivity on the ohms scale by inserting the probes directly into the product. Evidently the copper loading is not high enough for electrical conduction in a free state.