12V access in Gen2 R1S for light bar installation?

[jrd]

Thanks! Any idea how many amps it’s putting out

Do you mean how many amps are flowing through the cable I connected to the pink cable in the compute unit? It would be negligible as a ratio to the total current that cable (and likely anything that cable connects to on either side) can handle. It turns on a mosfet in my controller. The main power driving my lights comes from the terminal between the frunk and windshield, which is very thick copper. I don’t know how much flows through the pink Rivian cable, though, and I haven’t traced where the cable goes yet as it got a bit awkward.

I am making an assumption that the thick pink cable going into the compute unit is connected to equipment that can handle the extra current I’m drawing from it. I’m assuming this because the cable is quite thick copper that is designed to handle relatively high load and therefore can likely handle a little more than was designed for. I’m assuming that Rivian wouldn’t put a thick copper cable there if the connection never needed a high load. But, I could be wrong.


Also, I take no responsibility for anyone who destroys their car doing the same thing.

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[Polar]

@Polar thank you! Found the big red + connection point right where you said it would be. I'll try that next week and report back.

Did you have any luck?

Got my setup on my Gen1 done over the weekend.

 

[R1SColoradoPowPow]

@Polar, TLDR, yes! Got the switch and fog lights installed. Light bar had issues connecting to my rack, which has nothing to do with Rivian, just dealing with brackets and wind deflection. So phase 2 will be returning that light bar and going with a different option. I was waiting to post pics until I had it all wired up and complete (early November).

 

[good2go]

I managed to find a cable with power that turns off when the car goes to sleep. No idea what it’s for but it works for now. It’s the top most pink cable coming out of the bottom right plug in the drivers side compute unit. Looks like it is 14.5v when on and was sitting at 2v when the car was asleep. The thickness of the cable makes me think it’s unlikely to be data so hopefully a small extra load on it doesn’t affect anything. So far it has been fine.

I wasn’t game enough to disconnect the plug so I used an electrical crimp socket (the female bullet style) and opened it up a little more with long nose pliers, wrapped it around the back of the pink cable and slid it down onto the connector from the rear. Then I pinched it closed to hold on and slid the insulator over it. The zip tie is to help with strain relief.

Have you learned anything more about this? I assume this is power going into the cpu unit? Could you place the wire, just push one in and have the other go to your device?

how do you shut off power when working on the vehicle?

 

[jrd]

Have you learned anything more about this? I assume this is power going into the cpu unit? Could you place the wire, just push one in and have the other go to your device?

how do you shut off power when working on the vehicle?

I’ve been using bar lights and fog lights switched from a connection to this power outlet for a while now and haven’t had any issues (pulling very low current). The cable is providing power going into one of the compute modules, yes. I found that I needed to crimp the connector down in some way or another otherwise the cable would just fall out.

I didn’t shut off power while working on the vehicle, but that particular wire is not completely live when the car is asleep and it is low voltage.

 

[hammick]

I just completed my install using the 12v terminal. It works well.

I ran the controller cables in through the firewall rubber gasket on the drivers side in behind the kick panel.

The only thing I haven’t worked out is where an ignition, accessory or headlight power signal can come from (ideally from in the cabin for my particular light). That way I won’t drain the 12v battery with the controller circuit always being on. (Last resort is to add a dedicated switch and use a 12v source from the compute unit)

I measured power on the cables going into the headlight box but it looks like that is all digital with a 12v always on supply and two other data lines sitting around 2.3v and 2.7v. So can’t use that easily to determine when the headlights are on I think.

When the car sleeps the high voltage battery disconnects the charger from the 12v battery and the voltage drops from 13.7v (charging) to 13v or less. I could use this signal but would require an intermediate circuit which I’d prefer not to make. OBDII port was another idea but it has always on power.

If anyone knows where to find other power sources near the pedals on gen 2, I’d love to hear!

Any idea if that 12v under the red flip up cover is direct to the battery? Wondering if I can use a battery tender there.

 

[nealopp]

I’d love to see what you’re doing with the switch panel. I keep seeing all these silly installations with a freaking key fob remote for each light, which (for me) doesn’t track nicely with such an expensive truck!

edit: JK, I scrolled to the next post in the list and found it! Looks great!

 

[CaptTrev]

Hoping this might help someone looking to find a 12v ACC wire with “ ignition on” on a Gen2

there are a few switched 12v sources to use for a low amp draw “ switched on” 12v source to turn on a multi switch power device like the trigger 4plus or the Auxbeam like I installed

the pic here shows a harness under the back removable plastic trim behind the frunk on the drivers side

the pink as well as the blue w white wire are 12v on with ignition. And off when vehicle is locked - it took me a few minutes to figure out that they still on until 20-30 minutes after you lock - once the vehicle goes into sleep mode

hope this helps

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