https://www.tekonshaprodigyid.com/
https://www.curtmfg.com/part/51170
Or
https://www.etrailer.com/bc-2014_Lexus_LX+570.htm?Redirect=NoVisibleProducts
https://www.etrailer.com/multi-product.aspx?pc1=RED24FR&pc2=RED69FR&VehicleID=20143291090&HHYear=2014&HHMake=Lexus&HHModel=LX+570
https://www.etrailer.com/Custom-Fit-Vehicle-Wiring/Lexus/LX+570/2014/HM11143910.html?VehicleID=201431285
The wiring is all there, you just need to purchase each end. Rear end part is link above.
You can use RedArc like lx200inar mentioned or other brake controllers. There is thread in MUD how...
I’ve had the same issue with the non start.
I changed to this.
https://sdhqoffroad.com/collections/08-21-200-series-toyota-land-cruiser-sdhq-built-products/products/sdhq-built-complete-billet-battery-terminal-kit
@cruiserpilot maybe from this image you can get something out of what you are looking for.
Mine is from a local exhaust shop so it is not stock either...