Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
  • Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
  • The final cut of TMC Podcast #34 is available now with topics timestamped. We covered Tesla's rollercoaster prices, Toyota pushing junk science, Mike's new Model 3, Optimizing track mode for snow driving, FSD V11 apparently coming by the end of this week, and more. You can watch and check out the chat replay on YouTube.

12v for accessory in April 2018 delivered Model 3

I read elsewhere on the internet that the pictured, and held out by screw driver largest red wire in that bunch, can be tapped for 12v, however when I measure voltage with that red wire and the also pictured ground nut, or the grounding point next to the driver's seat under the trim, I get 2v.

What I had read this went to was the "cigarette lighter" socket in the center console, however measuring that postive terminal with the same grounding nut as negative gives 12v.

Why am I measuring 2v between the aforementioned two points? Does my early model Model 3 have a different coloured cable for the "cigarette lighter" feed, and is there another source of 12v easily accessible that wouldn't reduce the maximum amperage I could put through the "cigarette lighter" socket on the same side of the car?

What may explain the strange 2v PV, but based on evidence mentioned below likely not, is when I was putting the negative wires for the accessory under that pictured ground nut I had a lot of sparks and cabin lights/main display turning off and on, starting when I was untightening the nut. I figured I would still get these if screwing the nut back down (and indeed I did) so continued to remove the nut as fast as possible, and tighten it back down with the extra wires as fast as possible. A subsequent ~60 mile drive luckily didn't see any ill effects.

It is curious though that I installed the same accessory for a friend, using the same grounding nut as a negative connection point, without any sparking. Anyone with ideas about why this time and not last time?


  • IMG_20200907_182635.jpg
    493.4 KB · Views: 51
  • IMG_20200907_182720.jpg
    811.8 KB · Views: 39

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.