Tried using dielectric grease on my avionics connectors and got weird readings

I work on a lot of older Cessna panels and last week I decided to coat all the pins in dielectric grease before mating the connectors. Thought it would prevent corrosion. Next day I was getting intermittent open circuit faults that made no sense. Spent 3 hours chasing it before my lead asked if I used grease. Apparently on some low voltage signal pins the grease can act as an insulator. Wiped it all off with alcohol and everything came back normal. Has anyone else run into this with certain connector types?

3 comments

3 Comments

ray18924d agoMost Upvoted

Same thing happens with thermal paste on CPU pins, people think more is better and it just makes everything worse. There's a difference between protecting connections and blocking them.

charlienelson24d ago

Dude I literally fried a motherboard back in 2017 putting way too much thermal paste on, thought I was being extra careful but it just oozed everywhere. Learned that lesson the hard way for sure.

hugo_bennett22d ago

I swear ive read about dielectric grease being an insulator on low voltage circuits before, but 74 open circuit faults in a row? Thats wild man lmao. That would drive me absolutely insane chasing that down for hours. Glad you got it sorted with the alcohol wipe though, thats a solid fix.