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Rooftop Tents blocking brake lights (CHMSL)

jjswan33

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I looped it over the grey wires at the rear lamps, pointing away from the lights. Didn't connect anything for tail or stop lamps, just turn signals.
Can you clarify where you accessed these wires from?

So here's the thing: I suspect a 2-to-3 converter is the only device necessary to pull off this install. Will you have to tap wires? Yes, but you're going to need to tap for 12 volt anyway.

Pull the left signal/brake from the left black wire going to the tail light, and the right turn/brake from the right black tail light wire. Ground the white wire to the frame. The 2-to-3 converter will resolve separate brake and turn signal wires. If you only need the brake signal, cap the turn signal wires.

Saves you $120, a days' worth of work, and running 12v all the way to the gear tunnel.
I think I will try this method, seems more straight forward. Thanks for all the details.
 

Dark-Fx

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Can you clarify where you accessed these wires from?



I think I will try this method, seems more straight forward. Thanks for all the details.
Rivian R1T R1S Rooftop Tents blocking brake lights (CHMSL) PXL_20230410_224810801


I pulled the lights out but the cords are really short if you don't pull the service loop put. Probably just as easy to do it from inside by stripping back the tape.
 
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jjswan33

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The thick wires (gray or what you called black) and the opposite wire which has a pink stripe, are power and thin (two middle wires) ones are communications I believe. Not 100% certain since I didn't scope them out.
So I pulled out this connector today and honestly I’m confused. The pink with blue stripe seems to be 12v but not switched by the blinker, brake or even parking lights, didn’t check if it switches off when the car goes to sleep.

The black/dark gray wire I couldn’t get a 12v signal in any scenario.

I guess I may have to look into induction loop method you guys used because this 2 to 3 converter idea seems over my head.
 

avigneault

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So I pulled out this connector today and honestly I’m confused. The pink with blue stripe seems to be 12v but not switched by the blinker, brake or even parking lights, didn’t check if it switches off when the car goes to sleep.

The black/dark gray wire I couldn’t get a 12v signal in any scenario.

I guess I may have to look into induction loop method you guys used because this 2 to 3 converter idea seems over my head.
I think the black wire is ground, and the two small wires are CANbus. The controller is built into the taillight assembly. Did you tap the black wire while it was connected to the light, or just run the tester on the connector?

I suspect you'd see voltage on the ground (black) when power is drawn through the taillight (and, in turn, sent to ground)?
 

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jjswan33

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I think the black wire is ground, and the two small wires are CANbus. The controller is built into the taillight assembly. Did you tap the black wire while it was connected to the light, or just run the tester on the connector?

I suspect you'd see voltage on the ground (black) when power is drawn through the taillight (and, in turn, sent to ground)?
Yeah I had it tapped while connected to the light. I too think it is ground but I couldn’t get it to work as a ground with my tester but I might not have been getting a good connection.

I presume if I get the Tekonsha and wire it into the left and right turns like @Dark-Fx did and then use the Curt 2 to 3 connector I should end up with a proper working brake light…. That is if I am understanding what you guys did and what problem you were having.
 

avigneault

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Yeah I had it tapped while connected to the light. I too think it is ground but I couldn’t get it to work as a ground with my tester but I might not have been getting a good connection.

I presume if I get the Tekonsha and wire it into the left and right turns like @Dark-Fx did and then use the Curt 2 to 3 connector I should end up with a proper working brake light…. That is if I am understanding what you guys did and what problem you were having.
Yup, that's what I'm doing. Round about, but confirmed working.
 

jjswan33

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Yup, that's what I'm doing. Round about, but confirmed working.
So did you actually get this working? I have it setup with the 2-3 converter but I’m still getting occasional flashes with the blinker on but not constant flashes.

Edit: Added video. I guess it‘s better than no brake light.

 
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avigneault

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So did you actually get this working? I have it setup with the 2-3 converter but I’m still getting occasional flashes with the blinker on but not constant flashes.

Edit: Added video. I guess it‘s better than no brake light.

Are you only using the 2/3 converter, or the Tekonsha in between?
 

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avigneault

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I'm just using the Tekonsha at the moment, the 2/3 is on my countertop. My brake light flashes with either the left or right turn signal, but goes solid with the brakes applied.
 

jjswan33

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I'm just using the Tekonsha at the moment, the 2/3 is on my countertop. My brake light flashes with either the left or right turn signal, but goes solid with the brakes applied.
Ok thanks. Assuming I did everything right it does seem that at least some spurious signals are still getting through. I might play with it a bit more.
 

jjswan33

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To sum up my experience with this, I have a 'working' brake light but the blinker still causes some random flashes on occasion. On another note if I didn't have 12V power in the bed I would just tap into the purple/blue stripe wire coming from the tail light, as far as I can tell it is always on 12V. Also any concerns about battery drain with the Tekonsha unit can be put to bed unless you are powering some aggressive lights, in my case the power draw is <1W while not operating and at most 6W when the light is engaged.

Edit: For completeness I am using the Tekonsha unit combined with Curt 2 to 3 converter. I attached the Tekonsha sensors to the black wire (ground I believe) pointed away from the taillight on both sides as @Dark-Fx pioneered. Then I used the L and R turn signal outputs from the Tekonsha to the 2 to 3 converter and just the brake light output from the 2 to 3 converter.
 

Dark-Fx

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To sum up my experience with this, I have a 'working' brake light but the blinker still causes some random flashes on occasion. On another note if I didn't have 12V power in the bed I would just tap into the purple/blue stripe wire coming from the tail light, as far as I can tell it is always on 12V. Also any concerns about battery drain with the Tekonsha unit can be put to bed unless you are powering some aggressive lights, in my case the power draw is <1W while not operating and at most 6W when the light is engaged.

Edit: For completeness I am using the Tekonsha unit combined with Curt 2 to 3 converter. I attached the Tekonsha sensors to the black wire (ground I believe) pointed away from the taillight on both sides as @Dark-Fx pioneered. Then I used the L and R turn signal outputs from the Tekonsha to the 2 to 3 converter and just the brake light output from the 2 to 3 converter.
I probably wouldn't worry about the blinking behavior as long as it's only one or two blinks before it figures out it should stay solid.
 

jjswan33

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I probably wouldn't worry about the blinking behavior as long as it's only one or two blinks before it figures out it should stay solid.
Oh to be clear it doesn't blink when you use the brake, just an occasional blink when you have the blinker on. I agree it is probably fine, the main case where this might cause an issue is changing lanes on the freeway.
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