I am creating this thread to discuss access to power for those who desire modifications to the 2021 refresh Model S, such as adding a radar detector, dashcams, additional LED lighting, etc. This is being already discussed in multiple different areas, but not consolidated anywhere. I inadvertently hijacked the Diagnostic Port Index thread, where there is a lot of good information in there, but has taken a tangent off the purpose of that thread. I am asking the Mods to move many of those posts over here. There is also good info in this radar detector thread. For full disclosure, I do not have my refresh yet. I am just gathering information. More importantly, I deserve zero credit for this, as I honestly just compiling information from the hard work of others. I love modding my cars and often ride the coattails of others.
Personally, I am interested in both switched and unswitched sources. Switched is great for radar detectors, as one example, which have no major use while not driving. I want unswitched for dashcams, which I would like active while parked. I may want some LED features always on as well, which I can turn off manually through a separate remote switch when I desire.
Important notes:
Personally, I am interested in both switched and unswitched sources. Switched is great for radar detectors, as one example, which have no major use while not driving. I want unswitched for dashcams, which I would like active while parked. I may want some LED features always on as well, which I can turn off manually through a separate remote switch when I desire.
Important notes:
- There is no fuse box in the refresh. There are electronic circuits managed by the CPU
- Early reports showed that tapping into existing wiring can, but not necessarily, trigger all sorts of alerts.
- There is no standard 12V battery in the refresh for direct access. There is a Li-ion battery that does not have traditional posts. This was my preference initially, where I would have added my own separate fuse box.
- There is a cable in the driver’s lateral (outside) footwell behind the carpet that gives switched 12V access (thanks to @Hawkdriver for this discovery). It is also possible that this is in the passenger footwell as well (@Venom may have used this). These extra cables may be similar to the cable used for the tow package brake controller found on the X & Y (@Stewart ), and it is possible this $4.40 part from Tesla will allow an easy connection: BRAKE ECU ADAPTER (1072586-00- A). The part is not available online, so my guess is that you need to order it directly from Tesla. Proper fit has not yet been confirmed. The original intended purpose of this hidden connector is not clear. There is no known tow feature for the Model S, so maybe it is a left over from a similar wiring harness. Or, maybe something to do with ambient lighting upgrades.
- There is indeed an OBD-II connector under the dash in the driver’s footwell, as has been in all prior Model S's, pre-refresh. This provides unswitched 12V access with pin 4 = ground, and pin 16 = 12V. There are all sorts of OBD-II connectors online that will allow you to tap into this, including some with built-in step-down to 5V.
- As per the Diagnostic Port Index thread, there is a proprietary adapter hidden under the center wireless charging pad. In prior iterations of the Model S, this has been used for mods such as the lighted rear applique. This has switched 12V access. It requires a Maxwell adapter to either convert to OBD-II, or just to get access to switched power. I won't talk about this myself, as I have extremely limited knowledge of using this advanced port.
- @rhuber accessed switched power for his radar directly from the front camera. I am waiting to hear back on exactly how he did this. No alerts were reported. Personally, I am a little concerned about access such a vital camera.
- Finally, there is easy 12V access by plugging into the cigarette lighter adapter hidden in the center counsel.
