Front Seat Disassemble

[Luke Kidd 1]

Hello guys, wondering what the process for removing the front seat back is like to do with minimal experience, wanting to take it off to see if I can have a look at some of the wiring.

Thanks 

[Howplum]

What wiring issue do you have? If it's non functioning heated seats then from what I've read it's common, and possibly not easily repairable. Hopefully there be information on the internet about seat removal and dismantling. I'll bet they're heavy though!

[Luke Kidd 1]

Yeah was hoping I'd be able to see some of the wiring by just taking the back off without having to remove the whole thing, it's for heated seats, fuse works fine, all 4 of them aren't working and all 4 buttons light up green

[Howplum]

Exactly the same as my car then. I have an electronic workshop manual so will see if I can find any clues. However, because all four are not working would make me think that's it's unlikely to be individual heating elements, unless we're really unlucky.

[Luke Kidd 1]

Exactly what I was thinking, previous owner was under the impression they were working and didn't realise they weren't until recently, he was so honest about the rest of the car I have no reason not to believe him, so was wondering about the process of finding the wiring

[Howplum]

I found the wiring diagram for the front seats, but not the rears. Unfortunately it is in PDF format which doesn't seem to work if I insert it into this post.

Obviously this topic has come up before and here are a couple of previous topics from this forum:

https://us.lexusownersclub.com/forums/topic/54490-heated-seats/

There are plenty of topics on the internet, but as far as I can tell from a quick search this morning no-one seems to have come up with a definitive solution where all four are not working. Of course, the fact that all four don't work doesn't preclude the possibility that one or more of the heating pads is/are faulty. Presumably the driver's seat is the first to go.

LS400 heated front seats wiring diagram.pdf

[hockeyedwards]

Interesting, will be following this as I am about to take my seats apart for cleaning and some potential DIY leather repairs. None of my heated seats work either and had heard the elements are likely to go with age. I haven't done any testing fuse wise etc so will start simple and maybe reach your stage along the way!

[Malc1]

really  ??? didn't realise the rear seats were heated ............  don't seem to have an appropriate switch for them whatever, well, not on my Mk3 1995 car 

Anyway, does anyone ever have rear seat passengers 🤫

Malc

[Howplum]

I found this in my notes, which might help:

[Luke Kidd 1]

What's the image? Won't load for some reason

[Howplum]

It's a diagnostic procedure. I'll try again tomorrow.

[Howplum]

Maybe this will work:

https://portal-diagnostov.com/en/2020/04/09/power-seats-lexus-ls-400-1996-system-wiring-diagrams/

[Howplum]

Nope, wrong again !

If you search on this forum using the phrase "seat heater repair" (including the quotation marks) then my previous topic from a couple of years ago should pop up. I must admit I have not done anything about it yet though.

[Luke Kidd 1]

That's how worked great thankyou