I have an upgraded steering wheel in my 460 (the one with the wood upper and lower) but no heated steering wheel option in the truck... there is a blank where the heated steering wheel button should be. My understanding, though limited, is that the upgraded wheel has the heated feature but is the harness wired the same in all models? The dream would be to pop out the heated steering wheel blank and have a connection hiding behind it that I could plug an OEM button in to. My 80's Volvo was that easy to upgrade, so that is where this notion is coming from.


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Attached is the wiring diagram. In addition to the switch, it shows a relay and a "steering wheel heater control assembly". I would guess that those items are not installed, and if you are lucky, the wiring is in place already.

It appears that the "steering wheel heater control assembly" is p/n 55910-500100.

https://parts.belllexusnorthscottsda...591050010.html

EDIT:

There is this older five page thread on topic:

https://www.clublexus.com/forums/gx-...-retrofit.html