jmcgliss Posted May 9, 2019 Share Posted May 9, 2019 This post is a lesson in NOT using dialectric grease on battery terminals. Summary: electronic gauges must be sensitive to the quality of grounding. Last week I installed a quick-connect harness for my Battery Tender. The negative lead was attached to the negative "jump-start" stud stud in the engine bay. Then I applied some Motorcraft dialectric grease to the terminals to improve mating of the surfaces. All was good until the next day when engine heat and parking in the sun resulted in the instrument cluster flickering and eventually going dark. Battery voltage and charging systems are working fine. Cleaning the dialectric compound off the terminals and cleaning with Caig's De-Oxit spray for added insurance restored normal instrument functions. Conclusion: dialectric grease is not conductive enough except in high voltage applications like spark plug boots. There is some confusion online however, with some folks claiming to use it on ecu connections for waterproofing. Sidebar: the reason for installing the Battery Tender leads was due to battery draw that I discovered to be a glove box that was missing the actuator arm for the lamp switch. See separate topic. Quote Link to comment Share on other sites More sharing options...
R2D2 Posted May 10, 2019 Share Posted May 10, 2019 19 hours ago, jmcgliss said: This post is a lesson in NOT using dialectric grease on battery terminals. Summary: electronic gauges must be sensitive to the quality of grounding. Last week I installed a quick-connect harness for my Battery Tender. The negative lead was attached to the negative "jump-start" stud stud in the engine bay. Then I applied some Motorcraft dialectric grease to the terminals to improve mating of the surfaces. All was good until the next day when engine heat and parking in the sun resulted in the instrument cluster flickering and eventually going dark. Battery voltage and charging systems are working fine. Cleaning the dialectric compound off the terminals and cleaning with Caig's De-Oxit spray for added insurance restored normal instrument functions. Conclusion: dialectric grease is not conductive enough except in high voltage applications like spark plug boots. There is some confusion online however, with some folks claiming to use it on ecu connections for waterproofing. Sidebar: the reason for installing the Battery Tender leads was due to battery draw that I discovered to be a glove box that was missing the actuator arm for the lamp switch. See separate topic. Dielectric grease is not a conductor and therefore will not improve continuity but if your connections are tight it should not block current. I am a retired (41 years) communications and electrical specialist. I still keep a tube of it in my bag when I would work on all outdoor connection that are subject to damp conditions. If you want the proper grease for your purpose, use a No-Ox-ID or NOALOX grease. It does help improve conductivity and prevents oxidation and chemical reactions between dissimilar metal (i.e. copper and aluminum connections). You can find is in any of the home improvement stores, auto parts or an electrical supply company, a small bottle or tube goes a long way RAB 1 Quote Link to comment Share on other sites More sharing options...
jmcgliss Posted May 10, 2019 Author Share Posted May 10, 2019 Excellent info. Thanks for posting! Quote Link to comment Share on other sites More sharing options...
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