ive heard people say dielectric tune up grease (which doesnt make sense to me because doesnt that conduct electricity just as is nothing was on them in the first place?) vasoline?, battery terminal protector spray stuff...

 

with credit to Tony Athens, sbmar.com:

To put it another way, always use non-reactive, non-conducting, moisture displacing dielectric greases or lubricants when making electrical connections. These "moisture displacers" prevent moisture and oxygen present in the environment from contacting the metal surfaces of electrical contacts, thereby limiting corrosion and preventing the buildup of resistance within the connection. The basic principle used here is the "exclusion principle" and simply put, it is using a material (a dielectric grease or lubricant in this case) to occupy all of the spaces near and around an electrical connector that could otherwise be occupied by contaminants (possibly conductive) or moisture.

The grease basically keeps the metal contacts from oxidizing and building up resistance. It does not conduct and short things out. Old Skool used petroleum jelly. New stuff lasts longer.

By the way, if you have metal parts that will be submerged for weeks or more underwater, I always use Vaseline or diaper creme, mixed with a box of chili pepper, into a red goo. Little sea creatures don't like the taste and won't build colonies on it.

Vaseline also does a good job renewing door and window gaskets, as does silicone.

Vaseline, the versatile triumph of chemical engineering.

 

Dielectric grease is not really used as an electrical insulator. It is used to prevent water from coming into contact with electrical connections, therefore preventing the metals from corroding and causing a false contact. If you use regular grease it could get between the two points of contact and insulate them, rendering the grease useless in it's purpose to maintain the circuit.

 

It is important to note that metal contacts touch each other on a number of points, if you look at them at a microscopic level. Imagine two pieces of 60 grit sand paper touching, not 100% of the surface area is in contact with the other. The metal around the contact points dissipates heat under high current loads, to keep the points of contact from welding together. So big motors and such need big contacts, like a starter solenoid. Relays and the like are built to "wipe" the contacts slightly when operated to keep them cleaner. In the example of a sensor or light bulb connector, the metal to metal contact is the same with or without grease. The micro spaces that don't touch are filled with grease, and water and dirt and corrosion / oxidation is kept out.

 

Well put, my friend! Use the dielectric grease! It's really good stuff, clean the connections up really good, (I use a dremel tool with a little wire wheel on it and really clean the crap out of every connection I repair) then I put a little grease on the connectors themselves, put them back together, then slather a bunch more on the outside of the connections. I get great connections this way. I started doing this on my bikes especially my really old ones with questionable electrics and 6Volt systems and it always works great! And remember, crimp connectors are extremely temporary! I know this is not what you are talking about here but, when I connect wires together I use dielectric grease on those too. I solder them together, cover the connection I've made with dielectric grease and then use a length of heat-shrink tubing over the top of that. NEVER a problem ever again!!!

 

good info, guess ill make that my next project before the winter snow/salt mess! dielectric grease on everything lol. i did read somewhere absolutely not to use it on o2 connectors though... any particular reason those connections are different then the rest?

 

O2 sensors need a referance of Oxygen in order to operate. Most O2 sensors these days get that referance-Oxygen from the wire-terminal itself and if that wire-terminal is sealed, no more Oxygen referance.

 

This got me wondering, since I use dielectric grease on mine and haven't had any issues, so I called NTK to ask about it.
This is what he told me
Titanium sensor - ok to use dielectric grease on the electrical connector
Zirconia sensor - uses reference oxygen pulled in through connector, so not ok to use dielectric grease

The D1 sensors are Titanium. Sorry, but I forgot to ask if the DII sensors are.

 

learn somethin new everyday. wonder if i shoudl clean all the oil off of them than haha

 

I'd be surprised if the DII are Zirconia. Given how and where Land Rovers are driven, and that the connectors, at least the post-cat ones, are likely to end up covered in mud, it would be pretty dumb to spec Zirconia sensors.