2025 OT+ AUX Switches wiring

[cbra928]

has anyone....
1. located where the harness goes? (manual shows 2 generic spots in the engine bay)
2. what the part number is for the harness that connects to it to use the 4 switches?

 

[1 due]

has anyone....
1. located where the harness goes? (manual shows 2 generic spots in the engine bay)
2. what the part number is for the harness that connects to it to use the 4 switches?

Don’t know but my light bar is hook up to aux 4 installed by dealer sorry not much only had a day

 

[Wayne]

I used 0.25" female disconnects to connect to the existing connector (for a 2025 Overtrail) under the dash to power an amateur radio. The two widest pins on the connector provide a 15A circuit.

 

[jmercer46]

Has anyone contacted their Lexus dealer? Manual says “in order to connect accessories, accessory wire harness pigtails must be used. Accessory wire harness pigtails can be purchased at your local Lexus dealer”. I live in MT and we do not have a dealer. If anyone gets the Lexus part number, please share.

 

[jmercer46]

The new Toyota Tacomas use these which look right, but only 3 accessories

 

[jmercer46]

 

[Garauld]

Has anyone contacted their Lexus dealer?

I did last week. His response:
I was hoping to have more information and better news by now. I am unfamiliar with the request - the Service manager owns a similar vehicle and he is trying to dig into it with me. Also reached out to the field representative from Lexus and he is also looking into this for us.

 

[Finn GX]

still waiting on my 2025 OT, but would expect the 2025's would have the pigtail packed in a bag already, stashed in glove box or console, like in my Tundra and Taco?

 

[Wayne]

still waiting on my 2025 OT, but would expect the 2025's would have the pigtail packed in a bag already, stashed in glove box or console, like in my Tundra and Taco?

They don't. I had to improvise to connect to the plug under the dash.

 

[jmercer46]

Hopefully someone can be successful as it is an essential part of the auxiliary switch system.

 

[Garauld]

I reiterate that someone should take their OT to a local up-fitter that installs aftermarket light systems and get their expert comments. Maybe the connectors are like what comes on the Tundra.

 

[jmercer46]

They look very similar, just not sure if the Tundra has 4 aux like the OT does. O know the Taco version only has 3

 

[Siblue]

Tundra does not. I’ve added them on mine.

 

[jmercer46]

I may have found a guy that has built the proper pigtail. He is getting in a 2025 OT this week to test. I will share the link to purchase once he confirms.

 

[jmercer46]

Okay, this guy seems extremely knowledgeable and thinks this may be the pigtail we need for the AUX switches. He was unsuccessful in getting a client to bring his GX550 OT by to try, but really thinks everything should line up perfectly for all 4 aux and the ground appears to be correct too. Here is a link on ebay he has a business in NC and appears to have been doing this for around 27 years: Auxiliary Switch Connector/Wire Harness for 2024 Toyota Tacoma AUX Plug Adapter | eBay. See pic of listing. Here is his business: Shade Sound and Security, 5101-H Unicorn Drive, Wake Forest, North Carolina. Shadesoundandsecurity.com. When you order, just make a note that you are trying it for the GX, so he can put together some additional instructions for testing on the GX. If someone wants to order and test out and post the results that would be great. I ordered, but who know when I will have a rig to try........

 

[Lionxxx]

Hi everyone,

I wanted to share some quick feedback on the AUX harness I purchased via the eBay link mentioned earlier in this thread.

Fitment Experience
I drive a 2025 GX550 Overtrail+, and this harness plugs perfectly into the factory AUX connector under the dash.

The plug size and pin orientation match exactly — no trimming or modifications needed.

Once inserted, the connector locks in snugly with no looseness or play.

Very satisfied with the physical fitment and build quality so far.

Wire Function Uncertainty
However, I'm not fully confident about the function of each wire, and I was hoping to get some help from the community.

The harness has five wires, each in a different color.

I have only basic electrical knowledge and haven’t yet used a multimeter or test light to verify outputs.

 

[jmercer46]

I purchased also and changed the coloring of the wires to match the manual of the LX550. I also extended and added lume. Not sure if it works but the white and black grd and others seem to follow the tacoma with 3 aux switches and I assumed it to be similar to the current 4runner with 4 aux. I do not have a rig yet, so can not test.

 

[jmercer46]

My color coding now matches this

 

[Lionxxx]

I found that the AUX harness I purchased from eBay probably only fits Cable B, which is located behind the dash on the driver’s side.


The connector shape and locking tab orientation do not match Cable C in the engine bay.


Just wanted to share in case anyone else is trying to use this harness for AUX1 or AUX2 — it seems to be meant only for the Cabin B connector (AUX3, AUX4, and Ignition).

 

[jmercer46]

Did you buy the ebay listing above? Can you show pics of the connector end under the hood and the connector from the pigtail? Everything I have seen looks like the orientation is correct.