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Spare Switched 12V Circuit on Model S built after July 2014

wk057

Senior Tinkerer
Feb 23, 2014
5,692
11,813
Hickory, NC, USA
According to a Tesla "Tech Note" that was passed along to me, there is a 12V power source under the center console area in newer vehicles... I'll copy and paste that info since it seems pretty relevant here, appears to be for end users (since it specifically says Tesla isn't allowed to install third party equipment...) and I'm going to figure Tesla isn't going to mind. I haven't seen this posted elsewhere, and the document doesn't contain any language that would seem to prohibit passing it along like some of the other things I have seen.

---

Tech Note: Spare 12V Power Circuit


Tech Notes are announcements that help to communicate and track new information about Tesla Service concerns. Such concerns may or may not be VIN specific. These instructions assume knowledge of motor vehicle and high voltage electrical component repairs, and should only be executed by trained professionals. Tesla Motors assumes no liability for injury or property damage due to a failure to properly follow these instructions or for repairs attempted by unqualified individuals.

All Model S vehicles built after approximately July 11, 2014 are equipped with a spare 12V power circuit. The purpose of this power circuit is to provide a switched power source, reducing the risk of vehicle damage due to improperly installed third-party equipment.

To access the spare 12V power circuit, remove the RH center console closeout extension. The spare 12V positive circuit is the red wire with a white stripe on the gray 4-pin connector with 3 wires. NOTE: The spare 12V circuit shares the same black ground as the center console auxiliary outlet.


The spare 12V power circuit is tied to the accessory (ACC) rail and is capable of up to 11 A (150 W) of continuous load, 15 A (180 W) peak load.

NOTE: The spare 12V power circuit is protected by fuse F33 in fuse box 2 (Figures 2 and 3). Remove the rear underhood center apron to access fuse box 2

tnphoto.jpg


--

WARNING
: Use of improper external cabling or unsafe charging outlets can expose passengers to injury from high voltage electricity.
CAUTION: Tapping into the 12V system, including the spare 12V power circuit, is done solely at the user’s risk and can result in increased draining of, or potential damage to, the 12V battery. Potential effects of modifying Model S with third-party components can include, but are not limited to, reduced driving range and increased electromagnetic interference (EMI).
NOTE: Tesla does not endorse the use of third-party equipment and does not accept any responsibility for any damage incurred from installing non-OEM equipment.
NOTE: Tesla employees are not permitted to install or assist in installing third-party equipment.

---

Hopefully someone finds this useful, since it seems a little odd to have a user-oriented informational note not actually posted anywhere that I could see....
 

pgiralt

Supporting Member
Jun 16, 2013
1,520
155
Cary, NC
Nice find. I guess Tesla is in a difficult position on this one. They don't want to advertise something that is to be used for something they don't endorse, yet they went out of their way to actually create this circuit for the specific purpose of 3rd party components.

I wonder if this was added for the Taxis they deployed in the Netherlands. I would think you'd need some equipment for the meter and other such equipment. I think they went into service around October 2014, so a July build would be just about right to build and ship to Europe. Maybe they did this for commercial applications and they provide the tech note to certain 3rd parties that install that gear? Just a thought.
 

Fezzik

P100D, M3LR
Nov 6, 2014
554
60
Lincolnshire, IL
So this is switched as in turns on when you press on the brake pedal. To bad they don't have a constant on power source as well. Good to know. I'll plug in the radar detector into here. Thanks wk again for the info!
 

Cyclone

Cyclonic Member ((.oO))
Jan 12, 2015
5,058
1,143
Charlotte, NC
This is a great find! Hopefully something similar will turn up for the older vehicles! I have the unstitched 12V in the microphone cover by the headliner, but I would love something like this for anything I might add.
 

Fezzik

P100D, M3LR
Nov 6, 2014
554
60
Lincolnshire, IL
Just giving you a shout out wk. I am using this port for my radar and laser shifters. The other two wires to this is of course ground and also goes to the cig lighter port.
 

kuttakamina

Member
Aug 23, 2014
709
2
DC
This will be perfect for a dashcam. Sorry I'm a dummy when it comes to these things, but how could I convert that connector into a USB like input that dashcams like?
 

supratachophobia

Active Member
Sep 24, 2014
3,856
2,683
Columbus, Ohio
According to a Tesla "Tech Note" that was passed along to me, there is a 12V power source under the center console area in newer vehicles... I'll copy and paste that info since it seems pretty relevant here, appears to be for end users (since it specifically says Tesla isn't allowed to install third party equipment...) and I'm going to figure Tesla isn't going to mind. I haven't seen this posted elsewhere, and the document doesn't contain any language that would seem to prohibit passing it along like some of the other things I have seen.

---

Tech Note: Spare 12V Power Circuit


Tech Notes are announcements that help to communicate and track new information about Tesla Service concerns. Such concerns may or may not be VIN specific. These instructions assume knowledge of motor vehicle and high voltage electrical component repairs, and should only be executed by trained professionals. Tesla Motors assumes no liability for injury or property damage due to a failure to properly follow these instructions or for repairs attempted by unqualified individuals.

All Model S vehicles built after approximately July 11, 2014 are equipped with a spare 12V power circuit. The purpose of this power circuit is to provide a switched power source, reducing the risk of vehicle damage due to improperly installed third-party equipment.

To access the spare 12V power circuit, remove the RH center console closeout extension. The spare 12V positive circuit is the red wire with a white stripe on the gray 4-pin connector with 3 wires. NOTE: The spare 12V circuit shares the same black ground as the center console auxiliary outlet.


The spare 12V power circuit is tied to the accessory (ACC) rail and is capable of up to 11 A (150 W) of continuous load, 15 A (180 W) peak load.

NOTE: The spare 12V power circuit is protected by fuse F33 in fuse box 2 (Figures 2 and 3). Remove the rear underhood center apron to access fuse box 2

View attachment 81724

--

WARNING
: Use of improper external cabling or unsafe charging outlets can expose passengers to injury from high voltage electricity.
CAUTION: Tapping into the 12V system, including the spare 12V power circuit, is done solely at the user’s risk and can result in increased draining of, or potential damage to, the 12V battery. Potential effects of modifying Model S with third-party components can include, but are not limited to, reduced driving range and increased electromagnetic interference (EMI).
NOTE: Tesla does not endorse the use of third-party equipment and does not accept any responsibility for any damage incurred from installing non-OEM equipment.
NOTE: Tesla employees are not permitted to install or assist in installing third-party equipment.

---

Hopefully someone finds this useful, since it seems a little odd to have a user-oriented informational note not actually posted anywhere that I could see....

Shhhhhh, this was supposed to be a secret. And this is why we cant have nice things.
 

Fezzik

P100D, M3LR
Nov 6, 2014
554
60
Lincolnshire, IL
This will be perfect for a dashcam. Sorry I'm a dummy when it comes to these things, but how could I convert that connector into a USB like input that dashcams like?

CAREFUL. USB ports usually are 5volts while tapping this area is a 12-14 volt.
Also do you not want your dash cam on all the time? that is what I am doing with mine?
 

sbanks

Member
Jun 16, 2014
78
21
Swampscott, MA
This is great. I am installing trailer lights, the setup I have steals the signal from the brake & signal wires in the back but draws the power from a separate source, for which I will use this swtched 12v source. I've pulled the wire from the front console to the back of the car but there is not a pin in that connector where I would connect my wire. Any ideas where I could get a pin that would fit it?

Thanks
 

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