Administrators Moses Ludel Posted October 18, 2014 Administrators Share Posted October 18, 2014 There's a lot of chatter about the use of dielectric grease. Permatex suggests that Dielectric Tune-Up Grease is a good barrier to oxidation at plugs, connectors and terminals. There are some online comments at forums that say not to place dielectric grease on connector pins. I've gone to the Permatex site, and the information is vague: "Protects electrical connections and wiring from salt, dirt and corrosion. Extends the life of bulb sockets. Prevents voltage leakage around any electrical connection. Also prevents spark plugs from fusing to boots. Required for modern high energy ignition systems." Another quote from the Permatex site: Directions for Connectors: 1. Make sure ignition system is off. 2. Clean surface with Permatex® Contact Cleaner. 3. Coat both parts of terminal contact with Dielectric Grease. 4. Reassemble, maintaining metal-to-metal contact. - See more at: http://www.permatex....h.mSLOFJcy.dpuf Also, here's the PDF product information download from Permatex: Permatex Dielectric Tune-Up Grease PDF.pdf 69.55KB 0 downloads In the PDF, Permatex cites uses for the Permatex Dielectric Tune-Up Grease: TYPICAL APPLICATIONS • Spark plug boots • Distributor cap nipples • Battery terminals • Ignition coil connectors • Headlamp connectors • Trailer electrical connectors The "metal-to-metal contact" reference may create suspicion for some about "Dielectric Tune-Up Grease". I've used this product for years around tune-up work without reservation. I searched around and found an engineer's assessment of dielectric grease that suggests Permatex Dielectric Tune-Up Grease should work well on a variety of pin connector materials without creating any kind of resistance or barrier to current flow. This commentary is worth reading: http://www.w8ji.com/...tive_grease.htm, the author seems well informed, experienced, and he uses a scientific approach. According to the engineer, metal-to-metal pin contact should result if pins are clean and not tarnished, with or without dielectric grease on the pins. It's realistic to presume that the degree of conductivity is governed by the tension of the pin and socket fit, not whether we use dielectric grease. Whether or not you use the dielectric grease, I would use a quality electrical contact cleaner to get rid of the oozing material at your PCM plug and terminals. Make sure you flush out all residue and allow complete evaporation to prevent dilution of remaining grease or any issues with spark arc hazards. I would at least place dielectric grease on connector lips to act as an effective moisture and oxidation barrier. Personally, I'm good with the use of dielectric grease, others can use their own judgment. For me, the engineer at the www.w8ji.com site confirms and clarifies its intended uses. Moses Quote Link to comment Share on other sites More sharing options...
biggman100 Posted October 29, 2014 Share Posted October 29, 2014 Moses, im not sure how much of a difference it makes in the dryer areas out west, and even some parts of the southern states, but, in the northeast, dielectric grease is pretty much a have to have item if you want to keep corrosion out of electrical connections. As you know, i work on a lot of imports, Subaru being the main one, and some of the electrical connections are underneath the rear, especially evap canisters, and if those connections, as well as almost every electrical connection there is, arent coated in dieelectric grease, after they are properly cleaned, they will rot and cause all kinds of issues. Another reason i have found to use it though, fits very well here. Quite a few people in my area have off road, lifted, purpose built mud trucks, and i have seen many times where things like exterior lights, horns, and even misfires can occur after running a truck in mud, simply because the connections werent greased well enough, or not at all. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted October 31, 2014 Author Administrators Share Posted October 31, 2014 Good points, one and all, Biggman! There's a lot of controversy online about the use of dielectric grease. My most recent encounter with a supportive reference was the test of the Enerpulse Pulstar® spark plugs, which was publicized at the magazine and posted at the forums. Enerpulse emphasizes the use of dielectric grease on the terminal end of the spark plug. This is clearly a conductive and critical part of the plug. I also add dielectric grease to the insulator between the shell and terminal to create a moisture barrier for the spark cable boot. Thanks for sharing your experience here...Always great to see your posts! Moses Quote Link to comment Share on other sites More sharing options...
Tim Posted November 19, 2014 Share Posted November 19, 2014 I'll just add that in my over decade of modifying military aircraft with new electrical systems we never used any form of "electrical" grease on any connectors. Now that doesn't quite relate to Jeeps in the context of the thread. Nor is that to say you shouldn't use corrosion control type purpose greases with electrical connections. I am sure it has its place and I even use them in areas that I know will create an environment of corrosion. BUT, and my big but is to look into connector styles, and placement. All connectors in aviation that are critical and can be exposed to weather elements are designed to prevent that and equally in a aircraft you will have connectors that have no protections at all. This same mentality is evident in modern vehicle design. I am sure we all have come across those pain in the butt connectors that seem to be over engineered, but really they are not. If you know anything about cost benefit per cost per unit you will know it is mostly taken into account. This may not be true with aftermarket products or your own personal modifications. So keep metallic similarity (disimilar metals love to interact), connector seals and placement into account when working on or adding electrical systems to your Jeep. Quote Link to comment Share on other sites More sharing options...
KJS XJ Posted July 6, 2016 Share Posted July 6, 2016 Did my spark plug connectors and distributor on my 97 Volvo and its all good. Still unsure of the connectors associated with trailers or other multi-pin configurations as I have read that the grease could allow electrical transfer between pins, which in my limited experience sounds like a potential short, witch would suck. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted July 6, 2016 Author Administrators Share Posted July 6, 2016 I use dielectric grease sparingly. You bring up a good point, and this could be tested with a sensitive volt-ohmmeter. On non-weather tight plug connectors, with face-to-face connections and no seal around the joining points (like the common flat 4 or 7-pin trailer connectors), road debris is often conductive. OEMs often use dielectric grease on the pins inside weather-tight connectors. These kinds of sealed connections seldom give trouble: I could see an issue with trailer connections (like the example below), though the issue could be conductive debris and not the dielectric grease itself. Again, this could be tested with a quality volt-ohmmeter. Although Permatex actually recommends its Permatex Dielectric Tune-Up Grease for trailer connectors (see excerpt from the Permatex PDF above), I do not use dielectric grease on trailer connectors. Most often these connections are only temporary. I do, however, make sure that contacts and pins are clean and free of debris and corrosion: Has anyone had an actual experience with voltage leaks and dielectric grease on trailer plug connectors or anywhere else? Please share your findings... Moses Quote Link to comment Share on other sites More sharing options...
john patterson Posted March 5, 2021 Share Posted March 5, 2021 Dielectric grease comes in handy to protect the rubber and plastic parts of the connectors too. Lubricating rubber fittings to make them more secure without fusing is another vital role that this grease plays. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted June 4, 2021 Author Administrators Share Posted June 4, 2021 There are areas where you should not use dielectric grease, RTV sealant or anti-seize paste. One worth mentioning is certain oxygen sensors (O2 devices). Some O2 sensors draw ambient air where the wires enter the sensor housing. Sometimes There is a port like the vent opening shown in the illustration below. These O2 sensors depend on ambient air for a baseline voltage reading. Deviations from that point trigger the PCM/ECM/ECU to adjust or "trim" fuel mixtures. Be certain that you know where the O2 sensor's ambient air port or ambient air entry point is located. If at the connector, do not put dielectric grease, RTV sealant or anti-seize paste where it could block this air source. Know the type of O2 sensor used and how or where it draws ambient air. This generic O2 sensor image shows the vent to atmosphere. Air is sometimes sourced through a padding where the wires enter the top of the sensor. Do not plug this port or the area where the wires enter the top of the sensor: For more information on O2 sensors, Walker Products has a training guide on O2 sensors that is helpful. The guide explains the functions, troubleshooting and service needs of O2 sensors. Proper use of anti-seize on threads of new sensors is illustrated: https://www.walkerproducts.com/wp-content/uploads/2020/06/Oxygen-Sensor-O2-Training-Guide.pdf Moses Quote Link to comment Share on other sites More sharing options...
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