2024 First gen R1T Quad - HVAC - 3 way valve location? Help?

[UniqueRelic]

anyone know where to locate the hvac 3 way valve? for the life of me I cannot find it, I am about to pull the skid plates off to see if its by the front motors.

I have been able to locate/trace the two pumps. the heat/cool exchanger, if I am following the flow, seems to be somewhere under the a/c compressor

or beside the ac/dc module/inverter, but I don't want to start draining a/c lines if I don't have to, just to be wrong on its location. I am a fully licensed mechanic, and currently have the vehicle apart. and Already pulled the dash once before if its on the interior of the firewall.

it is my daily driver, plus been paying the bills the whole time so less down time for me the better. sadly will be putting the front end back together unless I can find it in the next few hours, (I need to pick up the wife at work at 3pm est)

smallish backstory
I have saved this vehicle from the scrap yard. its awaiting its salvage inspection by Rivian. (see pix below) they have not been kind to me, vehicle has been down for over a year due to the batteries unable to cool.

this caused the battery pack to never drop below 50C (122F) after dc charging in +30c (85F) ambient temps unless not used for long periods of time. overheating of the onboard computers causing the screens to go black during drives for hours on end. and ac charging to quickly drop from 11kw/hr to 1.7-2.4kw/hr with the cooling system working very hard.

the vehicle has been with rivian/authorized body shop since July 2025
I picked it up March 4th 2026

the body shop has already charged me a useless $16,000 this was to strip the vehicle down to frame, body off, and rebuild it to factory spec. this process took nearly 8 months. sadly when released to me it had no change in results (this is on top of the 12k in body damage repairs)
we threw whole new cooling system. 2 pumps. condensers, lines, cooling lines, cooling filter. 4 flushes 2 recharges etc.

Rivian Ontario Canada has been no help as they keep throwing me back to these "approved body shops" and refuse to even attempt diagnostics.
its very sad.

having the truck for a day to drive it home. dc charging only made the batteries go from 10C (50F) to 18C (47F), but still was unable to ac charge properly at home.

what I have discovered with the 2026.03 update that it now does a blue overlay on the battery bar and indicates loss range

so for curiosity I attempted a preheat cycle from my home while waiting for the wife before going to a local super charger. The odd thing I noticed is that it was heating the motors to over 140C (285F) and batteries remained 5C (40F)(pictues below)

I believe the "authorized body shop" may have installed the lines in the wrong position on the 3 way or it has malfunctioned. So instead of heating/cooling the batteries it was heating/cooling the motors.

the queue to get them to work on it again is almost 4 months and is approx 7 hours drive each way from my location. With no ETA and not to mention the absurd cost it will be again.
So while I wait, I'd like to replace this part or flip the lines.

here is the photos of the "salvage" damage March 2025

this is the vehicle after replacing everything that was broken behind the grill. all body parts were replaced including the hood.

almost ready for salvage inspection June 2025

first dc charge after repairs battery temps good. no issues but the climate was quite cool June 2025

observed ac charging issue/speed July 2025 - started at 11kw/hr then falling around the 2kw/hr mark, cooling was at max speed, battery at normal temp

nearly a year later ac charging attempt after replacing the cooling system march 06 2026

here is the photos of the attempts at preheat while parked, not in operation.
first picture as it is activated, second is near the end, last is when it was deactivated.

edited for mistakes and adding in Degrees F

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[sub]

I don't know the answer but rather than poking around blindly you could buy service manual access.

For $200 per month you can get access to the same information that the authorized shops have. This is really new, and I haven't heard anyone confitm that it is live, so it might be a good idea to call them before entering your cc details.


https://www.alldata.com/us/en/PR/rivian-oe-information

https://www.alldata.com/us/en/repair

 

[VandalSibs]

I don't know the answer but rather than poking around blindly you could buy service manual access.

For $200 per month you can get access to the same information that the authorized shops have. This is really new, and I haven't heard anyone confitm that it is live, so it might be a good idea to call them before entering your cc details.


https://www.alldata.com/us/en/PR/rivian-oe-information

https://www.alldata.com/us/en/repair

I'm excited for this, but we don't know when you'll be able to get Rivian-rrlated manuals and such from All Data. When you go to the DIY page and try to find Rivian, in the vehicle search, it doesn't come up.

 

[UniqueRelic]

Rivian Canada won't touch this because it is a salvaged vehicle so I'm spending it regardless of who touches it riven won't even charge me to look at it.

I have to satisfy their requirements of salvage title inspection first then they will reevaluate the vehicle and potentially look at it it is a lost cause there is no support from rivian at all

However good news I'm going to remove the plastic to get to it

Looks like I found it same bracket same harness it's hidden underneath the passenger side frame next to the rad

 

[godfodder0901]

so for curiosity I attempted a preheat cycle from my home while waiting for the wife before going to a local super charger. The odd thing I noticed is that it was heating the motors to over 140C (285F) and batteries remained 5C (40F)(pictues below)

I believe the "authorized body shop" may have installed the lines in the wrong position on the 3 way or it has malfunctioned. So instead of heating/cooling the batteries it was heating/cooling the motors.




here is the photos of the attempts at preheat while parked, not in operation.
first picture as it is activated, second is near the end, last is when it was deactivated.

edited for mistakes and adding in Degrees F

The motors heating is normal. The vehicle uses waste heat from the motors to heat the battery pack. What you're seeing is normal.

 

[Nixapatfan]

check you DM, might be in front of passenger side lower control arm.

 

[UniqueRelic]

The motors heating is normal. The vehicle uses waste heat from the motors to heat the battery pack. What you're seeing is normal.

I don't think you read the whole thing this is parked at 30° f not driving it's superheats the motors only to 140° c or 285 and does not increase the battery pack I have now rotated the two lines there is so much air coming out I can only assume from the battery pack the fans are nice and quiet and now I'm going to plug it in to an AC charger and see if it charges we'll update

Add another note with the lines rotated the motors no longer superheat when preconditioning but I think we have to wait for all the bubbles to get out of the battery pack before it starts applying heat

 

[UniqueRelic]

Well this is new..
I'm already on 2026.03 it was updated yesterday.
It's interrupted my testing. I guess at this point I'll slap it back together. And see what it does with the hoses swapped.
After this I am stumped.
Could the valve be faulty?
Does anyone know where the blue taped hose goes and the white? Just to verify was it in correct orientation or now is incorrect.
Currently seems to be better.

 

[impulsoren]

I am really unsure if it’s related but-2026.03 did something with battery temp monitoring that makes it super sensitive. I now get reduced regen from high battery temps regularly on hills where I never did before the update.

the battery-motor coolant flow has never seemed ideal for the huge battery mass, it takes a very long time for hot motors to actually affect battery temps in a meaningful way; I would imagine even the tiniest pocket of air could make the system completely ineffective. Can you measure temperature of the coolant lines in and out of the battery? IR thermometers are super cheap nowadays and that could tell you at least whether hot coolant is going in and transferring heat to the battery pack.

 

[UniqueRelic]

I still strongly believe there's an issue with this three-way valve switching the two lines around hasn't made that great of an improvement so I'm guessing how the valve is operated is typically it's open on the two line side and closed on the one line side then when it needs to heat the battery it's supposed to shunt off the line to the motors and direct the heat to the batteries or cold when it's needed I have a feeling that this valve is malfunctioned.

As for heat tracing I can do that however I don't have a hoist at my work I have it at home so I'll have to arrange a warmer day to pull the shielding off and trace it out

I just find it very odd that I can have the motors cooking at 140° c or 285° f and it doesn't budge the batteries at all.

At the same time if I plug in the AC it starts at 11 KW after about half an hour or when the unit gets hot it drops down to 2 KW the pump is at full speed.

I really hope that rivian Buffalo will eventually get back to me. Or at least we'll entertain me to bring the vehicle there because rivian Ontario is of no help.

They simply want me to scrap the vehicle yet there is absolutely nothing wrong aside from some sort of pump or valve or coolant filter that's blocked but they won't even attempt to look at it

So I'm back to square one trying to get rivian to entertain me in at least tell me what's wrong I'm willing to pay but they are unwilling to assist

 

[UniqueRelic]

I misspoke. not the battery meant to say motors!!

I misspoke. not the battery meant to say motors!!





tomorrow I will try to reach out to Rivian Buffalo again, and see if i can get this looked at without having to bring it to "an authorized body repair shop" and hopefully we can diagnose and repair the issues before spending fortunes on useless tare downs and rebuilds with new parts.

if anyone has a solid contact for the buffalo/nyc area that would be great. its only 7 -10 hours from my home.

 

[Nixapatfan]

Have you watched this video? that might answer how the valve works and where the blue line goes.

Might want to check all the sensor plugs and make sure they are all connected, I believe there is one for the 3 way right behind where the damage was on your truck.



I think it's this one from your picture

 

[UniqueRelic]

that video actually kicked off my hunt for the 3 valve
everything is connected with no errors on the Rivian service access

 

[godfodder0901]

I don't think you read the whole thing this is parked at 30° f not driving it's superheats the motors only to 140° c or 285 and does not increase the battery pack I have now rotated the two lines there is so much air coming out I can only assume from the battery pack the fans are nice and quiet and now I'm going to plug it in to an AC charger and see if it charges we'll update

Add another note with the lines rotated the motors no longer superheat when preconditioning but I think we have to wait for all the bubbles to get out of the battery pack before it starts applying heat

I did read your post. It does not matter that you were parked. You kicked off pre-conditioning, which causes waste heat from the inverters to warm the batteries. Hot motors is normal, even when not moving in this scenario. I do agree it is odd that the battery is not heating, depending on how long you let it heat. The motors /inverters on Gen 1 are not oil filled like Gen 2 so it is much less efficient for heat transfer.

 

[impulsoren]

I’m assuming you looked at the degassing bottle that is also right behind the damaged area. Apparently some undamaged Rivians are having that item crack leading to unspecified coolant problems that Rivians detects but doesn’t ever tell anyone about other than they need to replace it.

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