I'll definitely do what makes sense. The switch works as far as turning the heat on and off so I may just leave it as I'll never use it and it's probably not worth the hassle. Was hoping for an easy fix though.

 

I have the exact same problem described here, in a 07 ls460 at 136k miles. I can't say when the issue started as I bought it this way - the switch works to toggle the heater on and off but the light on the switch never goes off. It wasn't clear to me which fuse is the right one to disable it either, does anyone know?

Actually the OP mentions the heater is the same part with the parking assist, and that is fuse 3 on the passenger side so perhaps that'll do it, I'll go see. *pulled fuse* Well the steering wheel heater light stayed on still so I don't think that was it. Not sure how much time I want to spend since it functions fine besides the light always being on.

 

So did you find any solution for it ? .. i started havig the same problem first the heater switch will turn itself on and off later it was back to normal and after 2 weeks and today its just blinking

 

Sometime after my post above the car was involved in an accident that partially removed the front bumper but no other damage, and while having that repaired it resolved the weird light being on issue. I think it may have something to do with bad wiring/connector relating to the parking assist feature, as both that and the heated seat button are built in to the same module. As I paid someone else to do that work I can't narrow it down more unfortunately. But it was rather coincidental that work that touched the parking sensors in the front bumper happened at the same time as the light no longer staying on.

edit: I should add, in my case the heated steering wheel button light was ALWAYS ON, but the heat was NOT ON unless toggled on, and the button worked correctly other than the light on the switch not toggling.