LED Bar

[Gleneral]

Rest asured that i am a qualified service technitian.
I just want the exact info about How this is Done on on my 2018 full led teckna. This car has no simple wire to steal the signal from.

All other debatting is not helpfull.
Relaying the power is basic.

Help needed finding the headlight signal under the Hood

[estomax]

did you check the schematic link? That probably has the answer you are looking for as far as tapping into.

[powersurge]

I apologize if I sounded negative of what you want to do. You sound like you have things well in hand.. I am just cautious about wiring accessories to other things.

[patrickmoody84]

...want the exact info about How this is Done on on my 2018 full led teckna. This car has no simple wire to steal the signal from.

I know you never mentioned it, but if you were ever considering it, I'd forget CANbus. Tapping into and then attempting to decode the messages on the CANbus and then trying to make some use of them would be a substantial embedded software engineering project way beyond what you're trying to achieve.

Instead you could find where the fuses are for the headlights and take your signal from there. I couldn't find any info online other than for pre-2018 cars unfortunately, but it wouldn't surprise me if it's quite similar for the 2018 and later models. The PDM (power distribution module) which is located near the 12V battery on the 2017 Leaf has a bunch of fuses on its underside. It unclips and lifts up (dragging a whole thick bunch of leads with it) just far enough that you can turn it over and see the fuses. There's a key to identify the different fuses embossed next to the fuses themselves. Among those, you'll almost certainly find a pair of fuses each for the low beams and the high beams.

To get the signal from there, you could use a piggy-back fuse adaptor like I plan to, such as this one:
https://www.amazon.co.uk/gp/product/B07ML55GFL
It has the advantage of being completely reversible without leaving any trace that it was installed. So there's no need to strip back any of the insulation from the original wiring or install a wire-tap or anything else like that.

[Nubo]

It sounded like they want to tap power for a light bar (mucho watts) from the existing headlight circuit.. Which is crazy.

Also, It makes no sense to "want" all the lights to go on at the same time.... Lights on a car are a safety and issue regulated by law.

You cannot expect to turn on your lights AND LIGHT BAR all the time.... You will blind others and make them crash, and you will get big tickets.

What does it take to flip one switch on the dash when you want the extra lights.... Let's be logical....

I was thinking more along the lines of repurposing the fog-light switch, which would remove need to fish anything through the firewall. But my main point was that one needn't know any CAN info, but can simply rely upon existing light wiring to energize a relay that would send current to the new lights without overburdening the existing circuits. I was trying to add to the discussion and not trying to contradict or start an argument with you.

[Dala]

I did this on my Leaf yesterday, mounted a 100W LED bar. Highly recommended!

https://youtu.be/SBs5qJFJudI