HOW TO: Wire up your LED/aux lights to work with CAN-BUS driven hi/low/parking headlights.

well for the brights I want to plug these two 10” light bars from Baja Designs
And fogs I want to do these pods from Diode Dynamics.
Including some pics of the harnesses also. They all have 3 way switches but I don’t think I want those.

Basically what I’m asking is can I run the CANM8 for my light bars while keeping my fogs normal functionality (switching off when high beams are on)? Or do I need the IDR8?

 

Pretend you don't have OEM fog lights.
CANM8 will only trigger your light bar(s) when you activate your high beams (using the high beam trigger on CANM8).
Fog lights will operate as they normally would (high beams on = fog lights off), unless you change their wiring/trigger inputs.

PS:
Good to see this thread/info is serving a good purpose for everyone.

-99

 

Okay cool. So the pod lights if wired as fogs will not need CanBus communication. So I can just order the CanM8.
I drive on extremely rough terrain/roads so wire taps would be a potential problem…
What’s the best way to wire in the CanM8 without wire taps?

 

You'll need to do some more homework here re:fogs, as I never touched mine and thus have no idea how they're wired from OEM.
The LED headlights are fed constant 12V+ and only get triggered via CANBUS, hence why we use the CAMN8 device(s).
If the fogs are wired up the same, then you'll need the 8 output CANM8 box.
If the fogs are wired "standard"/old fashion then you just swap them out for lights of choice....but you will need to verify this, as I have no idea.
I'm sure there's a thread or two here about fog lights, and their wiring/etc.
GL

 

I've watched this thread for 3 years now and have yet to pull the trigger on execution. The order from abroad gives me pause as well as implementation. I can look more closely at the discussions here but is there a way to retain functionality of my push buttons that I added to the dash down to the left but also having the lights come on with high beams? In other words: Can they be manually turned off if I dont want them on with high beams in a particular instance or turned on by themselves if high beams are not activated? Hope this makes sense. The question seems convoluted in my brain here.

 

Makes total sense, and if you read my original post carefully you'll see that this is exactly how mine are done.
I don't go into full details there but note the 3-way switch(es).

Let's take high beams only as example:
Using the 3-way switch my light bar is wired in the following way:
Switch UP: wired to receive signal from CANM8 device (when high beams are activated), and runs to relay to activate the light bar.
Switch MIDDLE: simply "off"
Switch DOWN: light bar turns on independently of whatever the truck/light systems are doing; this trigger is fed by constant 12V+

Hope that makes sense, and I assume this is pretty much what you want to achieve.
-99

 

How did you determine which wires to connect the device to at the headlight? How did you figure out which wires signal High Beam?
Why is it connected to 2 wires? Pink and White? Same connector but my headlight harness wire colors are different.
Is it in the instructions for the device? Are the instructions vehicle specific?
.

 

You're looking for CANH and CANL

 

Perfect. Thank you.
Is there a reason that the CANL would need to be used if you are tying into the High Beam?

 

It's a communication protocol, that's what's needed.

That doesn't have anything to do with high or low beam.

 

CAN bus, short for Controller Area Network, is a robust, widely used communication protocol, especially in automotive and industrial automation, that allows devices to communicate efficiently and reliably with minimal wiring.
Here's a more detailed explanation:

• What it is:
  CAN bus is a serial communication protocol that enables electronic control units (ECUs) and other devices to exchange data in a reliable and efficient manner.
• How it works:
  It uses a two-wire system (CAN-High and CAN-Low) to transmit data, allowing multiple devices to communicate on the same network.

 

Right on everyone.
Reminder that you don't have to "plug into" CAN signal wires at the headlight. You can pick up the same wires/signal right at the ECU, inside the truck.
I was in "experimental" stage with all this when I did it, and I was doing a whole lot of wiring (regardless) at the time, so it was easier for me to simply do this at the headlamp plug, instead of searching out the right wires by ECU.
No wrong way to go about it, as long as the CAN signal is strong enough for this /any device to pick up.

Note:
The ODBII port inside the cab is not going to work, in case you're wondering...

 

I have verified the CANL/CANH at the OBDII does not work. Tapped near the ECU, works perfect.

 

I’ve been watching this thread and think this is all great. Thanks for originally posting this @99ways2die.

I don’t have a need for this now but book marked it for later. I saw on CANM8 site you can tie into many different CAN signals.

Anyone found any other options out there like this but a bit less expensive?

I would only do the contactless option but just wanted to chime in and see if others have found anything else.

 

Well, spent some time looking around and Crux Interfacing Solutions has something similar it seems: https://cruxinterfacing.com/product...ger-from-can-bus/#1655322254849-65ac057d-fda3

looks like they don’t sell direct but I found a vendor that has it for around $45. It’s not contactless though…

 

Reading that description, it's only a 2A power source off the OBD port. Does not listen to the canbus for signals.

 

Looks like it generates a 2A, 12V to a source after it reads the CAN? At least that’s how I read it in the manual https://cruxinterfacing.com/wp-content/uploads/2022/06/CAN-ACC-MANUAL_06.10.22-1.pdf

 

CAN is a data bus, the instructions say nothing about intercepting the data stream to execute actions. It appears as only a ACC power source.

 

This splains it. I think I got it ...
So instead of 12v power activating a device, like back in the days of the dinosaur,
The ECU makes a phone call and tells the device to turn on using CAN bus language. So one wire can provide several functions.

I'm in need of the CANM8 with contactless reader ... is ordering direct from UK my only option or are there local vendors?
I thought I read "Diode Dynamics" had it but can't find it on their website.

 

I found it pretty easy to wire up mine and now it triggers both my diode light bar in my grill as well as two Strands Lighting Division rounds. It works each and every time without a single issue ever since I installed it. It shipped pretty quick as I recall.

My fogs are wired to the existing OEM fog switch and I added a square switch for my ditch lights.

 

I ordered some of these square replacement buttons/switches

did you wire tap for illumination or hard wire? According to the YouTube comments this guy tapped the wrong wire
https://www.youtube.com/watch?v=P3YOAMF9NsA

Any advice for that part?
Also, if anyone is running a hybrid, where did you breech the firewall?

 

If someone didn't want to spend $120 to buy the contactless CANM8 system, could a person tie into the fog lights and have the light bar come on when the OE fogs are off?
(assuming the OE fogs have a 12v feed and not CAN bus)

Using a standard $6 relay with #87 normally open ... and #87a normally closed
#30 - Feed would be parking light / tail light so either fogs or light bar would only work if parking lights are on

In theory;
- the Aux LED lightbar would work anytime the parking lights are on and fog lights are off
- the Aux LED lightbar would be OFF anytime the parking lights are off
- the Aux LED lightbar would be OFF anytime the OE Fog lights were on
- the Aux LED lightbar would automatically turn on with high beam as the OE fogs turn off (and turn off with low beam if fogs are on)
- Could actually use the lightbar with low beam by turning off the fog lights

 

While what you're describing is doable, I have one problem with your design: use of "parking light or tail light 12v" for power source on the relay.
The reason to use a 20/30A relay is to provide a steady/proper/direct power source to the accessory. The way you have it drawn out is not much different from not having a relay at all. Imagine you're tapping into you parking light circuit to provide 12V to that AUX light bar.
I certainly wouldn't want a high powered accessory to run directly off a tap on parking/etc circuit.

 

I suspect the approach would be the relay described is the logic that will switch a second relay for the power. Personally, I'd shy away for disrupting vehicle wiring, no need to introduce additional fail points. CANM8 is the simple solution.

 

Yes, this relay would be the "switch" signal for the relay that feeds the aux light bar ... which would get power directly from the battery.
I agree that it's convoluted but seems doable.

 

This is what I did

https://www.tundras.com/threads/off...ction-mods-on-37’s.105476/page-2#post-2724488

 

Awesome. Thanks.

 

The code is cracked for "Light Bar to High Beam" ... (without the $120 canbus reader). Total cost was about $20.
2 standard relays, wire, loom, connectors, wire ties.
Installed, tested, and it is working as it should.

The light bar will always come on with parking light, low beam, or high beam ... until the fog lights are turned on.
So if you leave your fog lights on, the light bar will be off with low beam ... and turn on with high beam (since the fogs auto shut off with high beam)
I can also use the light bar with low beam by turning off the fog lights.
I did have to source the parking light signal at the tail light as I have the canbus style LED headlights. There may be a better option that I'm not aware of.
See diagram below:

 

Cheap(er).........................yes.
Working............................yes, mostly.
Elegant/"user friendly"........not really.

While what you've done was always doable, the complication (to some) of the wiring, and somewhat non-intuitive usage of the whole "system" doesn't compel me to give an A
It surely works and as long as you're satisfied then it's all that matters.

GJ for working out your own solution to suit your needs.

All of this for $20? Damn, my waterproof relays/connectors were about $35 each, never mind the rest of the crap to go along with 'em.
Keep an eye on that Chinesium (if not weatherproof/etc); I've seen a fair share of rusted out connectors and burned out relays in the past (usually due to "unfortunate" mounting location + element exposure + time).

 

Yes, it was always doable ... but nobody in here thought to mention it as an option.
True, it's not ideal for some as you will always have either fogs or the light bar on but I can't think of a situation where I wouldn't want one or the other on.
It is ideal for how I want it to function.
2 pack of waterproof relays are $12 on Amazon.

$13 2 Pack Waterproof Relay and Harness Kit 40A 14V DC, 5 Pin SPDT Car Relay with Heavy Duty 14 AWG Copper Wires

https://www.amazon.com/dp/B0C49J4JY7
I'll assume these are more waterproof than that canbus reader. One of the relays came with the light bar (and the fuse holder) Not a waterproof relay but I've had the same style in my '09 for well over a decade without issue. It would take about 90 seconds to replace if it ever comes to that.
... and I actually used components that I already had so just guestimating the total cost. I suppose you could spend a lot more than $20 but I would think that a person attempting this themselves would have some of this on hand already. Wire ties, elec tape, etc.