Anyone tap into DOME light for rock lights in 2017 LC?

[atsparkinson]

Looking to do a rock light setup similar to those seen in @Eric Sarjeant builds. He sent me several install photos which was very helpful!! Has anyone done this DIY w/o the help of Master Technicians at toyota... looking for the ELI5 explanation on how to do it.

Eric did inform me that i would have to use a digital relay but i dont even really know where to begin!

 

[eatSleepWoof]

Tapping DOME lights will require running more wiring than necessary, unless you want to use DOME lights being "on" as the switch for your rock lights.

The process itself is dead simple, but when it comes to electrical, it's a good idea to find a buddy that knows what he's doing, and have him show you how to do it. A cut of the wrong wire can cause serious issues with the vehicle, so electrical is not something I suggest people play guessing games with or learn no.

--

That said, you'll generally:
0. Disconnect the negative terminal on the battery, and ensure the terminal and wire cannot accidentally come in contact, by placing a folded towel or something similar in between them.
1. Install a switch somewhere.
2. Install a regular 12v automotive relay somewhere.
3. Run a (fused!) wire from the battery's positive terminal to the appropriate pin on the relay.
4. Run a wire from the switch to the appropriate pin on the relay to turn the relay on/off.
5. Run a wire from the relay's appropriate pin to your rock lights. When the switch in step #4 is turned on, the relay "passes on" the power from wire in step #3 to the accessory in step #5.

Or if you want to use the DOME light switch as the switch for rock lights:

3. Find the DOME wire that gets 12v power when the DOME lights are on, but does not get 12v power when the DOME lights are off.
4. Tap the wire from #3, install an inline fuse, and run the wire to the appropriate pin on the relay to turn the relay on/off.
5. Same as above.

 

[KLF]

I did hack into the dome light circuit, but at the rear dome light in the headliner, to control some additional LEDs on the lift gate. It was a REAL pain to get to, and difficult to get connected to that light. Be aware that the dome circuit actually switches the ground side, not the +12V side. Once I sat and stared at the wiring diagram for awhile, it started to make sense. This lets you trigger multiple independant circuits with several circuit feeds.

I have no idea why you would need a digital relay system. Seems like a traditional relay would work.

 

[prharper]

I've been following some of @Eric Sarjeant builds as well. His and others inspired me to purchase a Switch Pro. I've got the power module near the main battery and wired up. Waiting on Eric to supply me with the custom mount bracket for that piece. Ran the switch panel to the interior sunglass holder. Have another MUD member and vendor below trying to get a custom mount manufactured for it (The one referenced for Tundra Gen 3 in another thread does NOT fit 2016+ LC)

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Anyway, starting to get electronics connected to the Switch Pro (maybe some call this a digital relay). It's designed to eliminate the need for manual relays.

https://www.switchpros.com/wp-content/uploads/2019/03/SP9100-Rev1.2-Directions.pdf

In my case, I want to run some rock lights now. Connect + lead(s) of rock lights to one of the Switch Pro output wires. Connect negative lead of rock lights to a ground. Straightforward. Programmed button on panel works to turn on/off rock light(s).

To bring this back to the OP question, I need to find the right trigger to tap into to auto turn on rock lights when dome lights come on. Switchpro's example > use the external trigger input to turn on up to 4 outputs. Connect the Pink wire to an external trigger, it can be a high beam signal, reverse light signal, or a dome light signal to give a few examples.

Could use an add-a-fuse on the dome light fuse (I can't find the fuse for our dome lights. doesn't seem to be one labeled "Dome") Anyone know which fuse controls dome? That would be better than tapping or cutting in to existing factory wiring.

There are a few approaches to doing this with or without a Switch Pro or ARB Linx controller. Just trying to find someone who has done it and where is the best place to tap in to the dome. FWIW - Tundra has a DOME circuit/fuse.

 

[prharper]

Looks like it's located in Engine Compartment
Edit: This info below is incorrect for 2018. I suspect it's pre-face lift.

9

DOME2

7.5

Vanity lights, overhead module, rear interior light

Update: the other Dome fuse

53

DOME1

5 10 (From 2013)

Illuminated entry system, clock

 

[radman]

does the LC have stock puddle lights on the stock rocker panels (like the LX?)

I've been planning on tapping some rock lights into this bulb, but I need to make sure its not going to fry any wires in the stock harness.

 

[619TOY]

The dome fuse won't really do you any good in this scenario. It is essentially the same as connecting to the battery as it's a constant power fuse. You'll need to tap into one of the dome light wires post BCM as the BCM controls the actual switching of the dome lights. It looks like the easiest place would be one of the forward ceiling dome lights as they pretty much all turn on with all front four doors. I assume that's what you're looking for? Or all five doors? I believe all of the dome & courtesy lights are negative switched and you'll just need to use one of those switched wires to trigger an external relay, mechanical or solid state.

 

[prharper]

does the LC have stock puddle lights on the stock rocker panels (like the LX?)

I've been planning on tapping some rock lights into this bulb, but I need to make sure its not going to fry any wires in the stock harness.

My LC doesn't.

The dome fuse won't really do you any good in this scenario. It is essentially the same as connecting to the battery as it's a constant power fuse. You'll need to tap into one of the dome light wires post BCM as the BCM controls the actual switching of the dome lights. It looks like the easiest place would be one of the forward ceiling dome lights as they pretty much all turn on with all front four doors. I assume that's what you're looking for? Or all five doors? I believe all of the dome & courtesy lights are negative switched and you'll just need to use one of those switched wires to trigger an external relay, mechanical or solid state.

I think your on to something. The front door scuff plate with illuminated light "Land Cruiser" may be part of the courtesy lighting BCM. Tapping to that wire may work.

 

[prharper]

Just wanted to provide an update. I spent some time going back and forth with SwitchPro support. Very responsive and impressed. We tried a number of options to get their pink trigger wire working with the illuminated door scuff plate. That light must be fully controlled by BCM. Reached out to @Eric Sarjeant who came to the rescue. He confirmed with his installers that they use the light on the lower driver side panel above the brake pedal. That worked perfect. Many Thanks Eric. I installed two LED lights in the engine bay which now get triggered when opening doors. I'll add rock lights when I install sliders.

 

[atsparkinson]

Just wanted to provide an update. I spent some time going back and forth with SwitchPro support. Very responsive and impressed. We tried a number of options to get their pink trigger wire working with the illuminated door scuff plate. That light must be fully controlled by BCM. Reached out to @Eric Sarjeant who came to the rescue. He confirmed with his installers that they use the light on the lower driver side panel above the brake pedal. That worked perfect. Many Thanks Eric. I installed two LED lights in the engine bay which now get triggered when opening doors. I'll add rock lights when I install sliders.

do you have pictures on what you did? It would be very helpful

 

[prharper]

do you have pictures on what you did? It would be very helpful

Sorry, I don't have pics of the light I tapped in to but some info > there are two wires that go to that LED light. It's the Blue wire on the under dash light on drivers side. For Switch Pro, you need to make sure the Switch Pro is set for low side trigger.

In your original post, it appears you will need to add a relay and switch if you don't have something like a SwitchPro or ARB Linx.
Pic below of the two LEDs in the engine bay that are triggered by the courtesy light. I can also manually override with a switch on Switch Pro panel or via app on the phone.

 

[nwfl4runner]

Rock lights or courtesy lights? I say that because it might change what you need to tap into.

 

[prharper]

Rock lights or courtesy lights? I say that because it might change what you need to tap into.

I purchased 4 inexpensive "Rock Lights" to experiment. Seller description: 9W; LED Quantity: 3Pcs; CREE XBD; Weight:205g; Size: 2"; Install On Your Jeep, ATV, UTV, Motorcycle, Truck, Car, Boat, Golf Cart Underbody Underglow Light Kit. Use Them Under Your Vehicle Or As Interior Light, Off-Roading Light, Reverse Light, Dome Light, Neon Light LED Replacement, etc. Waterproof. Clear White.

My use case is:

1. To have lightning in the engine bay when needed. Added two of the above lights for that purpose.
2. Have lightning automatically turn on/off under the vehicle when entering/exiting the vehicle (i.e. better visibility in the dark in case I drop something or need to inspect anything) which can be enabled by unlocking doors from remote or opening a door. Have not added these yet as I'm waiting on sliders and determine how many lights I will use for this purpose. This is for function and not necessarily looks. They will turn off automatically after shutting all doors at x seconds.
3. Ability to manually override on/off anytime as needed by pressing a switch button.

It's accomplished by wiring one trigger lead from a smart relay (i.e. Switch Pro) to the OEM light under the lower driver side panel which seems to function as a courtesy light. The positive wires to rock/led lights are all wired to a Switch Pro controller (one switch wire connection).

 

[samster747]

Hey @Eric Sarjeant any chance you can make a video of these installs for us folks who can't make it all the way to Indiana? Would love to see some electrical install videos primarily so we can tackle them and know how to run wires as well.

 

[Eric Sarjeant]

Hey @Eric Sarjeant any chance you can make a video of these installs for us folks who can't make it all the way to Indiana? Would love to see some electrical install videos primarily so we can tackle them and know how to run wires as well.

Thanks for the kind words. Yeah, I’ll put a video together for you guys. My video editing intern (high school kid getting class credit for coming in 10 hours a week taking videos and pictures) is not aloud to come in because of Coronavirus. Once he’s back, we’ll make this.

the 2016+ are the ones that require a digital relay because the dimming dome lights pull variable power

 

[samster747]

Much appreciated @Eric Sarjeant. Some of the work you've done on these LC's, I would've purchased my HE from you with some work done but the deal with the wife was to stretch out the build over time and not take a big hit dollar wise up front. So I'm limited to building up on a year by year basis it seems. I do feel confident with the electrical work though having been a mechanic at Boeing and primarily doing electrical work. Though it would be nice to see some videos and how you guys did all your electrical work.

 

[samster747]

Just wanted to provide an update. I spent some time going back and forth with SwitchPro support. Very responsive and impressed. We tried a number of options to get their pink trigger wire working with the illuminated door scuff plate. That light must be fully controlled by BCM. Reached out to @Eric Sarjeant who came to the rescue. He confirmed with his installers that they use the light on the lower driver side panel above the brake pedal. That worked perfect. Many Thanks Eric. I installed two LED lights in the engine bay which now get triggered when opening doors. I'll add rock lights when I install sliders.

Ok I've been trying to think this through...so the pink wire off the switch pro, do I use a T tap and tap that into the blue wire running to the led lamp above the brake pedal? This will then trigger my rock lights to come on when I unlock the vehicle or open the door?

 

[prharper]

Ok I've been trying to think this through...so the pink wire off the switch pro, do I use a T tap and tap that into the blue wire running to the led lamp above the brake pedal? This will then trigger my rock lights to come on when I unlock the vehicle or open the door?

That should work. Make sure you go in to the Switch Pro app and configure the pink trigger to > "low" side and not high

 

[JetSurfer]

Thanks for the kind words. Yeah, I’ll put a video together for you guys. My video editing intern (high school kid getting class credit for coming in 10 hours a week taking videos and pictures) is not aloud to come in because of Coronavirus. Once he’s back, we’ll make this.

the 2016+ are the ones that require a digital relay because the dimming dome lights pull variable power

Thanks for that... I have my SwitchPro 9001 in and operational on my 2018 200, but I’d really like to get the trigger wires for high, low, and reverse set up.
Love your builds. If I had the upfront cash...

 

[Dashome]

Hello all, just wondering if there have been any updates on the video tutorials here. This thread is definitely heading into a direction I was hoping it would. I understand, if not. Thanks!