I use it inside connectors, it helps with any copper oxidation that may make them tight over time. As far as being waterproof, it probably helps make the connections more water resistant. Any exposed lubricant will trap dust so being conservative with application is in order. I use it on the spark plug boot holes too to prevent them sticking to the plug too. There is good and bad to this and it kind of boils down to personal preference.

 

I never put dielectric grease on low voltage electrical contacts because it is an insulator (which is what dielectric means)
It is great on glass part of spark plugs to keep boots from sticking and it is great for gaskets inside actual harness connectors but I would never put it on the actual metal contacts
if you do you are counting on contacts to squeeze it all out and if they do it ain't helping you with corrosion anyway
The last thing you want between 2 electrical contacts is an insulator

Most common old use for dielectric grease for me was on the follower on a points distributor as it lubricated with no possibility of conduction the electrons away from points- not used on the contacts of the points but on the follower for the points
also a lot of people use silicone grease on window tracks

 

While I agree with Digger84 that dielectric grease is an insulator, a properly functioning connector should have enough compression force to allow contact of the mating conductor surfaces while retaining a protective coating of the areas not in contact to keep as much oxygen and moisture away from the copper. I use it in every Amphenol AIT/MS servo power and encoder signal connector on my machine tools because it is a harsh, oily, wet environment and very subject to corrosion and things sticking together. Those connectors also have to grip well enough to break the insulation barrier

If your connector is worn out or damaged so that it can no longer provide good mechanical contact then grease will not help that existing problem, as nothing much will except repair or replacement. The grease being an insulator is one of the reasons there is good and bad in this and it comes down to personal preference.

I have read quite a few of Digger84's post on radio and other issues and have confidence he has extensive good knowledge and experience of what is needed and what may not be needed in a particular environment or connector type.
CRC manufactures a very good quality dielectric grease and they provide guidance on this as well, of course they are in the business of selling this stuff so there is probably the expected bias.

 

I use it on some connectors, especially on the seal area. Many OEM connectors have gold plated pins and sockets, so oxidation isn't the issue.

 

Just FYI... I use Burndy (brand) Penetrox liberally on my battery terminals ONLY as it is a conduction enhancer (due to the addition of various metals that Burndy adds during manufacture). It is also exceptionally good at blocking moisture and air, retarding corrosion. During my (45) years in the Electrical Trade, I've used GALLONS of this and learned to appreciate just how well it works. I would NOT recommend liberal application in the small vehicle push / snap-in type connectors that are used for sensors that send info to the ECU's simply because it IS conductive grease. A very small amount LIGHTLY smeared on the metal portions would be okay but "packing" the plastic snap connector (I believe) would give some issues that might be hard to track down. To reiterate... I highly recommend this for use on battery terminals! ... Mike

 

Thanks for the informative video on the CRC product. I figured I'd "copy-cat" and add a link that better explained why I didn't recommend the Penetrox for the small type vehicle connectors. I hope this is useful information as well?

 

I'll agree lots of people use it on contacts and claim no problems
I'll also say I don't and also have had no issues but I don't live near the ocean or in the rust belt

I'll also report that I have yet to ever see any oem assembled automotive connector that was slathered in dielectric grease when originally built (and I have taken apart a least a few thousand of them and only residual silicone I have ever seen on them was on the sealing rubber of the connector never felt any on any of the pins of the hundreds of pins I have removed from oem connectors) but i have seen lots of guys slather it on a later sometimes in an almost ritual performance

 

With today's "make it as cheaply as possible" mentality, I'd believe that the automakers wouldn't spend the money (time and material) on something that "may" make the vehicle last a little longer (esp given what terrain some Wranglers are used on).? If I actually DO pull the pin and do a frame-off rebuild on a "pre-OBDII" Jeep... I WILL use the CRC Dielectric grease on all of the connection points / terminals and the Penetrox on the battery posts and starter (high-current) terminals and "High Temp" Anti Seize on bolt threads.

 

As much as I might want to believe in the electrical contact squeeze fairy and her ability to remove all dielectric grease with the the slightest metal to metal contact, it just won't track for me for a couple of reasons

1) IF slight contact pressure removed all residual grease lubricant then why use grease on gears or wheel bearing or the dielectric grease on the distributor points cam or on power window mechanisms

2) when you pull apart a bare spade or pin connector (no attached plastic connector to complicate things) the force required to separate the metal connector halfs (due to the metal to metal friction contact) is reduced if they are first slathered in dielectric grease which I can only explain as dielectric grease being present at the metal to metal contact

Perhaps the magical electrical contact squeeze fairy only completely removes residual grease for believers so it is best I continue to avoid it on low voltage contacts

 

If you're doing long term connections, try to use gold plated connector contacts. No grease is needed to protect them from building a dielectric oxide layer like can happen with tin or bare copper connectors. Dielectric grease works well on the seal area of weatherproof connectors to prevent water intrusion and makes it easier to disassemble.

As for the argument to use dielectric grease on the connector pins and sockets, why not run some resistance tests with a meter? Isn't that really all we're talking about?

 

nope we are talking long term in 100s if not 1000s of pin connectors in one vehicle with varying area of contact and contact pinch force and with today's interconnected low voltage digital bus communications all it takes is one intermittent one to wreck your day, (and intermittent issues are the bane of diagnosis) which is, in my opinion a more likely explanation than the few cents the grease costs as to why I have yet to see it on the pins of an unmodified/untouched oem connector

but like I said many guys have used it for years and report no issues

I do think the separation force is a more honest way to prove it still exists at mental to metal contact and will admit usually not an issue but if it adds to the problem at just one crucial and problematic connection it is one possible problem too many for me

As an aside my wife has a 1983 280ZX turbo 2+2 she bought from someone else in 1991 and recently had a beautiful repaint restoration
Then it developed a miss
It is EFI but very primitive by today's standards
I spent months trying to fix that miss and it kept getting worse
Finally one time when I pulled the ECM connector I happened to notice some previous genius had repaired a damaged pin connector in the harness plug by simply stuffing the end of a stripped wire into the back of the damaged connector pin hole
It had worked adequately for decades but eventually it became an issue
I will grant that even with a couple junkyard harness connectors removing that broken pin and a good pin from the junkyard harness was very difficult but eventually accomplished and harness properly repaired
So sure compromising a connection just a little mostly still works but it can create a diagnostic nightmare that I would rather avoid

 

The more I follow these posts the more adamant my dislike for "modern" vehicles get! People spend (High)Tens to Hundreds of Thousands of Dollars on vehicles that, more likely than not, will spend a LOT of time and money to troubleshoot and maintain. I still fail so see the advantages of having a computer (1) blow the horn, (2) control all of the lights, (3) maintain the heating / cooling, (4) tell us our gas caps are loose (I know...emissions), etc etc ad nauseum? One of the Forum Members (rightfully so) pointed out that "hundreds if not thousands" of individual terminals are present in today's vehicles (each one adding one more potential point of failure). I am NOT against computers that control "anti-lock" braking or even "Realistic" levels of engine efficiency but the "peripheral" items like I mentioned are totally unnecessary IMHO. I'm VERY certain that someday soon a group of "brilliant $@B bureaucrats and tree huggers" will pass laws that make vehicles older than XX years illegal to be on the road... but hey... this what "everyone" wants, right?

 

There is unfortunately a significant incentive for mandated and regulated complications added to vehicles at both the government and the automaker level

Based on my experience in medicine the most hotly debated unsettled topics long term are issues where there is usually little significant advantage to either position hence no overwhelming evidence to push the vast majority one way or the other and although I have a position on my personal use of dielectric grease I am willing to agree that as far as I know there is no overwhelming evidence to use it or not use it

 

One take away I have from my years as an airworthiness/certification engineer, investigating failures, is that various greases are reactive to some metals, to some degree. The National Lubricating Grease Institute (NLGI) has recommended tests for the industry to test for compatibility of a grease with the metals in the intended application. One such test is for adverse corrosion, which is more prevalent in non-ferrous metals. While investigating a particular airplane crash where grease was implicated in the failure of a flight control system, I learned more about grease than I ever gave a thought to.

 

along same lines the old 84 300 ZX had a recall to replace headlight switch because corrosive grease was used inside the switch

"
Recall 29321 [USA]: Vehicle description: passenger cars.system: headlight switch.
Impure lubricating grease used in the headlight switches could contaminate one or more contact points. Operation of the headlights could be delayed or not light when the switch is turned on or when the dimmer switch is operated. Consequence of defect: loss of head lights while driving could result in a vehicle accident.
replace headlight switch as necessary.
vehicle description: passenger cars.System: headlight switch."

from

1984 Nissan 300ZX Issues and Complaints

Consumer complaints and issues filed for the 1984 Nissan 300ZX

dot.report

 

along same lines the old 84 300 ZX had a recall to replace headlight switch because corrosive grease was used inside the switch

"
Recall 29321 [USA]: Vehicle description: passenger cars.system: headlight switch.
Impure lubricating grease used in the headlight switches could contaminate one or more contact points. Operation of the headlights could be delayed or not light when the switch is turned on or when the dimmer switch is operated. Consequence of defect: loss of head lights while driving could result in a vehicle accident.
replace headlight switch as necessary.
vehicle description: passenger cars.System: headlight switch."

from

1984 Nissan 300ZX Issues and Complaints

Consumer complaints and issues filed for the 1984 Nissan 300ZX

dot.report

"Corrosive Grease" is not Dielectric Grease.

 

I only use Di-electeric grease on the Battery Terminals and it's connection points. I also use the Green and Red felt pads on the base of the battery terminals. It works very well and keeps corrosion to a minimum which is highly desireable. As far as Di-Grease on Sealed Electronic "Male/Female" Attachments I leave it alone as they are sealed within the connection housings. Keeps them nice and clean the male/female housings... Been doing such for 30+ years with great results... YMMV... But I doubt it.

-Hams

 

One experience I can share about dielectric grease was on my 2014 pickup. I had put HID headlights in it, which required ballasts and relays for heavier power wires. I was having problems with the relay sockets corroding and failing from water intrusion. I replaced the components and put dielectric grease on them. The corrosion stopped. They worked until I finally replaced them with LED headlights.

Currently, on the same truck, I still have a relay packed with dielectric grease, that runs the aux driving lights. I haven't touched that relay socket in a lot of years now.

 

Use dielectric grease liberally. Yes, it's an insulator, but it will NOT prevent a good connection. In my 50+ years as a licensed electrician and ASE Certified mechanic, (yes, two careers), I've repaired many hundreds if not thousands of electrical joints and connections that failed because a dielectric grease was not used. I have never found one instance where a dielectric grease caused problems. Yes, it will hold dirt on the surface, but that dirt will be prevented from entering the contact surfaces by the grease.

 

Nice response. I've also had decades in electrical situations, mostly in TV broadcast vehicles. Know how many electrical connections are in those? I also HATE crimp-on connectors.

Look at ANY push-and-click connector with a magnifier (I use photographer's lupes) and you'll see a LOT of possible contact surface, but very little actual contact. Most of the time the amount of contact is a lot higher than what the to/from wires pass, so they work well. But the contact surface areas/scratches are NOT anywhere NEAR 100% of the possible contact surface. That's where corrosion starts to occur. I've always gobbed any kind of dielectric grease on/in connectors except those that are gasketed and watertight. For gasketed/watertight connectors I will use a contact cleaner and place a super minimal amount of grease on pins and at the tip of sockets. But for the typical pin/socket connectors and ring terminals, I clean them, wash out crimped areas with contact cleaner, and re-squeeze the crimp, clean the contact surface and nut/bolt with emery cloth or sandpaper until they shine, grease it all up, and refasten the connector and/or rebolt the ring, then grease over it neatly, but completely. BELIEVE ME, any micro burrs and general contact of the connector and connection will create their own contact and won't even show a fraction of an ohm of resistance. Once done and hooked together and/or bolted, I gob a 'neat' amount of grease over the whole chebang and wipe off excess. Years later the area has some dirt and dust caked into the grease, but wiping it off and disassembling it reveals just what was left before application of the grease. Sometimes I'm amazed at how clean the contacts still are. ZERO, and I mean ZERO, corrosion, and very obvious scratches and clean spots where 100% contact was made.

This method keeps water and air pretty much out. Vehicles are the worst in terms of corrosion and contact degradation because all of the elements are there: moisture, dirt/debris, oils, brake fluids, antifreeze, road salt and deicing chemicals, hot and cold temperatures, and, of course, electrical voltages. (and bad contacts that heat up and cool, expend and contract metals....)

I bought a 2012 Wrangler with 82K on it this past January. It was/is in amazing shape. After a couple of mud baths it started popping off codes like the whole thing was gonna blow up. Of course I panicked and started looking at what they were and replaced a few sensors at little expense. Given the age of the Jeep, I figured why not? After talking to the very experienced folks at Endangered Species in Holyoke, MA, I was encouraged to clean every ground I could find, including ones under exhaust heat shields. The fellow at the counter has a few samples of ring connectors with 3-4 sensor ground wires squished onto one ring and bolted to the block to show me.....it's a very common problem to have dirty/corroded ground connectors. So, before I did what I was advised, I started measuring resistance and was amazed how I'd have 6-10 ohms resistance on measurements from battery ground to a block or chassis ground connection through a wire that was 3' long!

So I started cleaning...and cleaning. I even ran some braided wire grounds between the chassis and engine block. The infamous 4 sensor grounds to the ring connector/engine block behind the passenger side exhaust heat shield? It wasn't too bad, but I cleaned it, resqueezed it, sanded the ring and mount area shiny, remounted it, and ran a thick battery cable from the chassis to the same bolt on the block. What was a few ohms resistance turned into very near zero....like .03 ohms instead of 3-6 ohms. From the battery ground to any spots on the chassis or engine block, they're all comparable, any reading negligible.

I've had NO CEL's, mileage has improved, as if the vehicle is brand new. The cam position sensor and knock sensor I replaced were inexpensive. I even kept the old cam position sensor because it likely was NOT a problem...maybe I'll need it someday.

I respect anyone who feels di-electric or conductive grease is the only way to go...if it works, it's great. My problem is that when conductive grease flows, so does the electricity. The application is needed in some areas, but I'm not sure about vehicles; others may be. Di-electric? I've never seen it flow anywhere, but under extreme heat, it may, but so what? Something will get dirty.

I saw a Jeep at a meet & greet event...beautiful diesel model. Under the muddy hood was a muddy engine. ALL contacts were dry and bare with nothing protecting anything. The battery contacts were dry and grey. I showed the owner and told him that nothing is protecting the actual contact surfaces, and the battery terminals and connectors will soon be glazed over at points of contact. In time they will heat up creating little corrosion and resistance, then more corrosion and larger resistance, and efficiency will go down, and as stated above, it's happening everywhere there are chassis and block contacts. He saw it, and offered that he'll remove the battery terminals and clean, remount, and grease them, then at least coat the chassis contacts and whatever he could get to. I showed him mine and even with the grease on them, they looked cleaner and were definitely more protected than his. he got it. I wonder if he'll be looking to sell his in a few years....

 

so I.ll stick with oem avoidance of a mess of grease that attracts grit and becomes an even bigger mess that is very difficult to remove completely
again I don't live in rust or salt belt or near an ocean but in desert southwest

I still have many that old
58 willis wagon
60 TR3
76 triumph Bonneville
83 280zxt
80s honda 250XL
92 YJ
93 ZJ

never found a justification to put it on an electrical contact in any vehicle

 

...
again I don't live in rust or salt belt or near an ocean but in desert southwest

...

never found a justification to put it on an electrical contact in any vehicle

I think that's an important point. The desert southwest is where commercial and military planes are stored due to the low humidity, which doesn't promote corrosion. The salty ocean air or moist air of much of the country is a different game.

 

My TR3 also had a hand crank that could be inserted thru a hole on the radiator

Just to clarify that my non use of dielectric grease is not a unsupported position I asked 3 engineers I spend time with
1) a mechanical engineer with a masters degree who has spent the last several years working almost exclusively with electrical cables at Sandia national labs no further specifics as everything he does is classified
2) A retired electrical engineer who spend the last few decades developing and testing sonar equipment on nuclear subs again all classified
3) A guy with masters in electrical engineering who spent several years at electric boat followed by several years at the very large array in Socorro NM

All three agreed that in their opinion better not to add dielectric grease to automotive connection pins

 

None of what they do is about automobiles.
And all connections that they are dealing with aren't cheap-assed crimp pins made out of God-knows-what that have noticeable corrosion after a few years. .
They have wire that's sometimes gold or platinum or silver and are spec'd to the highest degree. I had colleagues who were in military/defense, especially aircraft guys, who laugh at cheap stuff in cars.
Some connectors/connections they use cost about the price of a car.
Terrible comparison. Not even close to the same genre.
Cheap connections need more than prayers to endure.
When you run across cold connections, corrosion and intermittent contacts, and grease them and never have to worry about them again, believe me, grease works. If you live in a dry climate, don't drive in snow, salt, and mud trails everything works forever.

 

Well as long as ever engineer I know and asked and the automakers don't add dielectric grease I'll stick with that over what some experienced repair technicians say is best

but best of luck to you

 

I'm an engineer, too. And it's a long debate. But don't confuse military and avionics' wires and methodology with what's in cars. Automakers don't grease and sell more cars when they fail, right? Also provides service income. Just like bodies don't rust as they once did. Rust wasn't invented this century, but all of a sudden cars don't rot anymore. Be an engineer yourself and explore your own perceptions and analyze your own failures. If engineers were so smart we would not have failures, right? But perpetual use costs money. All I need to see is the corroded and intermittent ring connections and stupid crimp connectors that, if soldered would never go bad, on Jeeps, to know what "engineers" do. What Jeeps have are planned failures. You never see that in aircraft or other "can't fail" electronics/wiring. If you're smart, you may not grease the first time, but after a cold-connection failure once, you'll grease the second if you don't want to have it again.

 

And FYI the VLA guy lost his job over covid vax and now works at a rual northeast power supply company and still has not changed his opinion on dielectric grease

 

So he doesn't believe in science. Not a good reference, Digger.
And, last I saw, power supply companies are HUGE on conductive and dielectric compounds in mechanical connectors/terminations. I've not seen new power panels without grease in years. In fact many quality crimp connectors (if there is such a thing) are coming with grease inside of them now. It just stops moisture/dirt/dust contamination. Believe in science.

 

no those tubs were closed off

 

"So he doesn't believe in science. Not a good reference, Digger."

You obviously know nothing about medicine or this case.

For decades as an aviation medicine doctor I did work including doing write ups for the FAA pharmacy and therapeutics committee and we had a standing policy, no use by safety sensitive position people (pilots and air traffic controllers) until a full year after a full FDA approval for any new medicine except when just minor variation of existing medicine.
Then after a full year of general use a full review was done to determine what if any restriction was appropriate then and and only then was any use by safety related individuals approved.

We violated that for political reasons NOT science

The drug companies shut down the controlled studies almost immediately by using the vax on the control group

I say vax rather then vaccine as the CDC had to change their published definition of a vaccine to include the vax

The CDC manipulated the data as I told the Senior Regional Flight Surgeon (who is currently the Federal Air Surgeon)
I advised her that the CDC was carefully wording the data, to include the data from before the vax was even available and data from when the vax was not widely available, to pad the numbers showing more hospitalizations and deaths in unvaxed.

She said she doubted it but would ask on her next call to CDC and next week on the national call with all the flight surgeons she said I was right about how the data was put together.

So I ask you if for the first 6 months all cars are red then for 3 months 11 of 12 cars are red then over next few months the non red cars steady increase is it fair to use the early all red months to suggest being red causes cars to get in more accidents than other colors?

That is exactly what was done!

That electrical engineer had a medical contraindication to get the vax but the political correct Australian executive running the VLA was determined to fire anyone not getting the vax

The EE took his case to the the state and was the only employee who won because he should have gotten a medical exemption and he did provided the appropriate paper work

You are very very out of line to say he does not believe in science and if that is how you decide things I will not consider your conclusions at all well thought out

 

Thread closed due to derailment.