[GUIDE] LED light bar installation on LED headlight Leaf ZE1

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CeladonCityNPC

Well-known member
Joined
Apr 29, 2022
Messages
68
On the past three vehicles I've owned, I've installed a LED light bar for improved visibility in winter. LED light bars are becoming commonplace and legal in many countries, but they need to turn on and off with the high beams. Installation on a car with halogen headlights is trivial; you can wire in a relay to the high beam cable to turn the light bar on and off. However, on a car with LED headlights, such as the Tekna/SL spec Leaf ZE1, there is no separate 12V cable for high beams. What can you do?

Worry not, for here is a solution! After a couple of weeks of research last winter, I figured it out. There's still surprisingly little documentation regarding this online, and the Leaf is not even listed on compatibility lists, so I thought I'd make a post about it, maybe it'll save someone else some time. I'm sure professional installers will have no problem wiring this all up for you for a price, but doing it yourself can save a few bucks. Be careful when attempting this project; as always, I have tried my best to explain everything but cannot be held liable for any damages to your car.


End result first. I chose to install it inside the front grille:
Q9y712Y.jpg


Things needed:
The LED light bar itself
Regular LED light bar relay wiring
CANM8 Cannect Highbeam (or similar device)
A couple of meters of around 20 AWG wire
2 x 5 amp fuse
Fuse tap (thief)

First part - relay and light bar itself
So, first things first. You need to wire in the LED light bar and the relay as normal; that is, light bar in the front and relay power cables to the 12V battery and the light bar. In the end, you should have one cable left: the cable which needs 12V input to activate the light bar relay. You can easily test that everything is connected properly by checking that if you connect this cable to the 12V battery's positive terminal, the light bar will turn on, and as you disconnect it from the positive terminal, the light bar turns off. So far so good? Great! Let's move on.

Second part - CAN sniffer
Next question is, how can we get 12V to this cable only when the highbeams are on? For this, there are surely many different solutions available, but the one I used is a device called CANM8. It could be described as a "CANBUS relay"; when it senses through CAN messages that the high beams are on, it provides 12V out through a connector. This device should be quite universal and work with most cars, but the Leaf is not listed on the compatibility lists on their website for some reason. I've been using it for a year though and it works perfectly.

There are five cables on this device, and they should be color-coded like this:
White = CAN HI
Blue = CAN LO
Red = Switched 12V input
Black = Ground
Purple = 12V output when highbeams are on

Third part - installation inside the car
Easiest way to wire this in is to install it under the driver's dash (if you have a left-hand drive car) and wire it where it needs to connect. We can start with the red and black cables; the red cable is easy enough to route to the left side of the dash panel, where the fuses are located. Pull off the panel cover and you should see a number of low-profile mini fuses. On the top, there is one 5 amp fuse that is switched; that is, it only turns on when you turn the power on in the car. This is important because otherwise the CANM8 will stay on 24/7 thus draining your battery. With a multimeter, you can verify it's only on when your car is on. Remove the 5 amp fuse and insert the fuse tap into this socket, while installing the two 5 amp fuses in the fuse tap (one new, one old.) While the Leaf ZE1 fuses are micro fuses, a mini fuse tap is a perfect fit regardless due to the same width of both fuse types.
2-Add-A-Circuit-Fuse-Tap-Piggy-Back-Fuse-Holder-APS-ATT-Mini-Low-Profile-Flat.jpg_Q90.jpg_.webp


Next to the fuse panel there is a bolt connected to the chassis. Unscrew the bolt enough that you can pull the end of the black cable around this bolt to ground it. Screw the bolt back in and ensure the connection is secure.

Fourth part - CAN we do it?
Now we come to the interesting part. Under the dash panel of the passenger side, there is a thick bunch of wires, as below:
vzSuMKr.jpg


It may be easier to reach these cables by removing the glove compartment first. I chose to do it without removing it, but you definitely need a good work light to see anything, and a bit of patience. This bunch of wires is more or less covered by tape that you may need to pry away to reach the cables. The CAN HI and CAN LO cables of the car are here, and we need to tap into them. We want to make 100% sure we DO NOT CUT THE CABLES, but instead use a utility knife or similar to remove around 1 cm of the outer coating from two of them and then we tap into those, soldering our new cables into them and using insulation tape to cover the crime.
In order to connect the CANM8 (under the driver dash) to the CANBUS (under the passenger dash), you'll need your 2 meters of wire. It makes sense to run two cables from under the driver's dash to under the passenger's dash at this point, before we tap them into the CAN cables. In order to pull the cables through the middle dash panel, I chose to use an "opened" wire coat hanger. Push it through the back of the dash center first, tie the cables to the hanger, and pull it back through to the other side.

The cables from the thick bunch we need are as follows:
Blue wire (silver markings) = CANBUS HI
Pink wire = CANBUS LO

After tapping into the CAN cables, and pulling the long cables under the driver dash, solder them into the white and blue cables of the CANM8 accordingly (HI and LO).

Now we should just have the purple cable from the CANM8 left under the driver dash and the relay cable on the other side of the firewall in the "engine bay". We must get these two connected. There may be different ways to connect this cable, but I chose to run it through the firewall through the pre-existing hole just under the driver dash. There is a thick bunch of cables running through the firewall there, covered by a rubber gasket. I used the sharp end of my coat hanger to push through the rubber and pulled it out on the other side under the hood just enough to tie my relay cable into it, and then pulled it back through the rubber inside the car. This was easily the most frustrating part of the project, but I managed to emerge successful in the end. I soldered this cable into the purple cable coming out of the CANM8.

Fifth part - testing
Everything should now be connected; double check your wiring. If you are confident that you did everything right, just turn on the car. The CANM8 LED should either glow a constant green or blinking green, signaling that it is sniffing on the CAN or it is still looking for your car. If the LED is red, there is a problem with wiring, most likely your CAN HI/LO cables.
If the LED is green, turn on your high beams, and you should see the light bar turning on as well! Tuck away the CANM8 under the dash (I secured it in place using zip ties) and you're good to go.

I've been using this setup for around 12 months now and it has been 100% foolproof so far. Even the automatic high beams work great with this setup.

If there's interest in this guide (let's see when winter arrives again) I could update this thread with more photos if needed.
 
Great post, thanks.

CeladonCityNPC said:
The CANM8 LED should either glow a constant green or blinking green, signaling that it is sniffing on the CAN or it is still looking for your car.

How does the CANM8 know the right CAN bus messages for high beam on/off? Does it somehow scan the messages, and look up a table and say "Aha! This smells like a Leaf, so I use this entry in the table for the high beam on/off control"?

Or perhaps it's a standard PID, like for engine RPM? A quick search didn't turn it up.

I'm just curious how it works. Wonderful that it does, without the user having to be too technical.
 
coulomb said:
How does the CANM8 know the right CAN bus messages for high beam on/off? Does it somehow scan the messages, and look up a table and say "Aha! This smells like a Leaf, so I use this entry in the table for the high beam on/off control"?

Or perhaps it's a standard PID, like for engine RPM? A quick search didn't turn it up.

I'm just curious how it works. Wonderful that it does, without the user having to be too technical.

The CANM8 attaches to CAR-CAN, where the Body Control Module (BCM) sends out a 0x60D message, that contains the headlight status bits (MainBeam/HighBeam/Blinkers etc.). This message is the same shape as the Nissan 370Z, and most likely other Nissan's aswell. This is why it is a plug'n'play install.

X7RJEPd.png
 
Dala said:
coulomb said:
How does the CANM8 know the right CAN bus messages for high beam on/off? Does it somehow scan the messages, and look up a table and say "Aha! This smells like a Leaf, so I use this entry in the table for the high beam on/off control"?

Or perhaps it's a standard PID, like for engine RPM? A quick search didn't turn it up.

I'm just curious how it works. Wonderful that it does, without the user having to be too technical.

The CANM8 attaches to CAR-CAN, where the Body Control Module (BCM) sends out a 0x60D message, that contains the headlight status bits (MainBeam/HighBeam/Blinkers etc.). This message is the same shape as the Nissan 370Z, and most likely other Nissan's aswell. This is why it is a plug'n'play install.

X7RJEPd.png

Wow, the mighty Dala is in my thread! Hälsningar från Helsingfors. Cool to hear how the device works. Thanks for the insight!

Hope I didn't mess up too many details in my post. :lol:
 
So you didn't have to specify a "Nissan" flavour of CANM8, or do anything to tell it that it's in a Nissan?

It's pretty impressive if it's at that level of plug and play.
 
coulomb said:
So you didn't have to specify a "Nissan" flavour of CANM8, or do anything to tell it that it's in a Nissan?

It's pretty impressive if it's at that level of plug and play.

Yeah no specifics were needed. The compatibility list of different car makes and models is quite long actually, making the device even more impressive.
 
How on earth did you manage to attach your led panel under the license plate?
I tried it yesterday and couldnt for the life of me figure out how to attach it down there.

You have any tips?
 
Cajun said:
How on earth did you manage to attach your led panel under the license plate?
I tried it yesterday and couldnt for the life of me figure out how to attach it down there.

You have any tips?

Ah, missed that part in my post. My LED panel came with nuts and bolts to attach it to the surface below it -so I put mine inside the grille. It just fit through the holes. I found it would shake a bit during driving so (don't lynch me) I drilled two small holes on the inside lip of the bumper and fixed it in place using zip ties. This also allowed me to fix the angle in the end.

There are lots of license plate LED mounts online as well, but I like the "stealth" installations more. From the front, you can't even see I have a light bar unless it's on.
 
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