Off-Road Lights Triggered by High-Beam Switch Circuit?

[SkeeterBait]

I'm kicking around the idea of creating a "trigger" circuit to illuminate an LED off-road (or street legal) driving light bar in addition to a manual switch.
When the driver selects the high beam headlights, a relay circuit switches on the auxiliary lights and vise-versa when low beam is selected.
As advanced as electronics are today, there must exist some type of component to sense a 12 Volt current flow to trigger a power relay that won't upset the sensitive CAN BUSS. I've been out of electronics for awhile now and the grey matter has gotten a bit more dense! Haha
What do you guys think?

 

[mtnrider]

I used the high beam wire going into the BCM under the dash to trigger a 12v relay and used diodes to protect it from feeding back into the BCM. I also used a switch to interrupted the relay signal if I just want my regular high beams and no aux lights with it.

Works great and no issues with the trucks circuitry


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[SkeeterBait]

I used the high beam wire going into the BCM under the dash to trigger a 12v relay and used diodes to protect it from feeding back into the BCM. I also used a switch to interrupted the relay signal if I just want my regular high beams and no aux lights with it.

Works great and no issues with the trucks circuitry


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Wow... Awesome! Please excuse my ignorance, but what is a "BCM"?
Also, is it possible to get a wiring/circuit schematic for these PW's?

 

[mtnrider]

Wow... Awesome! Please excuse my ignorance, but what is a "BCM"?
Also, is it possible to get a wiring/circuit schematic for these PW's?

Body control module, it's under you driver side dash.

It looks like this...




And this is a basic circuit of what I did. I changed it up some but this kind of gives you an idea.
I can activate the aux light with the high beams or disable it by flipping a switch. I can also turn it on with it's own separate switch.
I eventually tied all this into my factory aux switch's with several other lights so mine got a bit more complicated.



I do not have the diagrams for a 2020 (mine is a 16 2500). I am sure they are almost identical but you might want to track down a 2020 diagram just to verify.

 

[SkeeterBait]

Killer...! You're an awesome friend! Thanks, I understand this circuit perfectly. This will solve my dilemma exactly.
Robert

 

[Overlander]

I did this exact thing on my Land Cruiser. When on rural highways I like to run with my offroad lights on. Makes a big difference in spotting suicidal wildlife. However, I didn't like that I was slow to the trigger when killing them for oncoming traffic. Wiring them to the high beam stalk makes it a very fast kill. I additionally have an 'enable' switch that determines whether they're active or not. So I can have OE high beams only or OE high + Off Road Lights.

One nice thing about ordering with the Upfitter (VSIM) module is that you have outputs you can use as triggers. For example:

 

[WY-Dave]

I did the same in my Jeep but triggered the relay off the high beam wire. It was fine until I put in LED headlights. The relay would chatter. I just moved it to a dedicated circuit.

 

[2manyprojects]

I also have set up "flamethrower" mode with a high beam signal on my '85 Land Cruiser, using three position double-throw Carling switches. Flip one way for on-with-highbeam, off in center, or just on. Works great.

With my new Tradesman and the sophisticated CANBUS system, I unfortunately don't have the aux switch or VSIM options. I just bought a SwitchPro 9100 system, and it allows for two triggered inputs, and programmable on/off from a trigger for up to 4 of the 8 controlled circuits. It's not OEM, but looks very straightforward to install and program. Haven't got it running yet, but it's the best alternative I've found if you don't have the aux and upfitter options on your Ram.

 

[UTAHPWRWGN]

Wonder how that would play with the auto high beam function...

 

[mtnrider]

Wonder how that would play with the auto high beam function...

The wire I tapped into is the output to the high beam so when ever it is on the light bar will be on. Should work the same with auto high beams.


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[mtnrider]

I did the same in my Jeep but triggered the relay off the high beam wire. It was fine until I put in LED headlights. The relay would chatter. I just moved it to a dedicated circuit.

Was this a newer year jeep?
One thing to mention is I have LED bulbs in my headlights and set it to LED with AlfaOBD. If it's a newer vehicle with halogen bulbs it's probably using a PWM signal to drive the light and that is causing relay chatter. Setting to LED disables that.


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[UTAHPWRWGN]

The wire I tapped into is the output to the high beam so when ever it is on the light bar will be on. Should work the same with auto high beams.

Can't decide if it's good thing or a nightmare in the making given how often I run with high beams and how that could be really problematic for other drivers not to mention attracting unwanted attention from LE. I also like having multiple layers of lighting that are independant. Just sunday night I had 90+ miles of dirt road from the rim of the grand canyon back home and within the first 3 miles the fuse holder for the 40" Feniex AI bar decided to melt. Was really glad to to have my ARB Intensity's on the bumper totally independent and functioning for the 3 hour trip home in the dark and dust.

 

[mtnrider]

Can't decide if it's good thing or a nightmare in the making given how often I run with high beams and how that could be really problematic for other drivers not to mention attracting unwanted attention from LE. I also like having multiple layers of lighting that are independant. Just sunday night I had 90+ miles of dirt road from the rim of the grand canyon back home and within the first 3 miles the fuse holder for the 40" Feniex AI bar decided to melt. Was really glad to to have my ARB Intensity's on the bumper totally independent and functioning for the 3 hour trip home in the dark and dust.

Honestly, auto high beams would drive me crazy either way Lol. You could just disable them?

I have multiple levels of lighting as well, I can operate them independently or all on with the high beam if I choose. Circuit get a bit more complicated then that simple diagram I posted but it's doable.


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[UTAHPWRWGN]

Honestly, auto high beams would drive me crazy either way Lol. You could just disable them?

I have multiple levels of lighting as well, I can operate them independently or all on with the high beam if I choose. Circuit get a bit more complicated then that simple diagram I posted but it's doable.

Love the auto high beams. Takes all the stress out of using them whenever possible.

 

[olyelr]

Love the auto high beams. Takes all the stress out of using them whenever possible.

Agreed!

My half ton is a big horn and dosnt have them. Dosnt have the auto wipers either...drives me nuts!

 

[UTAHPWRWGN]

Agreed!

My half ton is a big horn and dosnt have them. Dosnt have the auto wipers either...drives me nuts!

Yeah, I specifically hunted for a truck with the safety pkg and no sunroof. Once you have rain sensing wipers, auto hi beams and adaptive cruise it's tough to want to go without them.

 

[Arctic Taco]

I have independent driving lights and will be doing the Sport headlight upgrade pretty soon. I would imagine all these newer automatic options can make it pretty smooth driving wise, but given location and use I prefer simple and manual as much as possible.

I routed an 8 conductor cable to the 3 round switches located up in the overhead console that control the relays (mfg supplied wiring harnesses) for the KC fogs, and the Lightforce moose lights= bright eyed and loud which keeps the moose running away...

 

[Havn2muchfun]

I hated the auto high beams on mine, had to shut them off. To many times the highs wouldn’t come on with no traffic at all. The only thing that I could figure was the highly reflective road signs confused it into thinking there was oncoming traffic. Never cared one way or the other about the wipers lol.

 

[Overlander]

EU market Porsche's (and others) have multi-element LEDs that turn on/off individually, shaping the beam pattern to avoid blinding oncoming vehicles as well as sign reflection glare. Thank antiquated US DOT standards that don't allow us to adopt this technology.