Toots. My drivers heated seat backrest doesn’t switch off

[Toots]

My backrest heats up even with the switch in the off position when I start my 2015 RX450h.Can anyone advise how to rectify

[Herbie]

Faulty switch?

Have you got the necessary tools to do some electrical fault-finding, such as a multimeter for instance?

[Toots]

Yes but how do I access the switch to test it.I can’t see how to get at it otherwise I could have checked .I am comptent with electrics

 

[Toots]

On 8/10/2019 at 12:42 AM, Herbie said:

Faulty switch?

Have you got the necessary tools to do some electrical fault-finding, such as a multimeter for instance?

 

On 8/10/2019 at 12:42 AM, Herbie said:

Faulty switch?

Have you got the necessary tools to do some electrical fault-finding, such as a multimeter for instance?

Yes and I’m okay with electrics but I’m having difficulty using this forum so please bear with me 

[Toots]

How do I access the switch to test the wiring and the switch 

[Herbie]

No worries Arry. You'll find lots of very helpful people on here but you'd be amazed at how many people ask for help (especially electrical help) but who don't have the necessary tools or test gear to do anything anyway.

2015 was they year Lexus introduced the series 4 model and if you have one of those this may or may not help you as these are the instructions for the series 3 cars:

[Herbie]

Just had another thought.

The switch is just on/off isn't it, with no provision for switching the seat cushion and seat back heaters independently?

If the switch is faulty and passing power when it shouldn't, then you may also have a faulty cushion heater as well, or both cushion and back would be hot, not just the back.

I'll try to get the wiring diagram up for you later. EDIT - here you go:

[Toots]

Just checked .Access is different.My Rx450h is the 2015 mk4 so I’m still not sure how to get to the switch to test.

[Herbie]

Oh well, sorry Arry.

You can actually buy a block of time to access the workshop manuals on the Lexus website here https://www.lexus-tech.eu/default.aspx

I can't remember the exact pricing but something like £3 for an hour, £7 for half a day, going right up to over two grand for a full year.

Good luck in sorting it out.