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Seats adjustment stopped working after buttons exchange attempt
Hi guys,
I have 2008 RX350
Some time ago one of adjustment buttons (tilt forward) for driver seat stopped working. I bought a complete seat for similar model (I think bit older) looking nearly same apart from armrest shape. I extracted the buttons panel out of it and tried to replace it at my RX350 2008. My rx turned out to have 2 plugs for the adjustment panel. The older one I bought has got 1 only but it fits my lexus. I tried to connect it. Since then all adjustments are gone. Even for the passenger seat.
Fitted back original buttons but no luck. I've checked the fuse and it's ok. Where to look next?
As you have found out the hard way, you should NEVER attempt to mickey mouse something that has different electrical plugs. There are differences in the 2nd generation model years. For electrical stuff, 2004 to 2006 (the RX330) is one way and the 2007 to 2009 (the RX350) is another. You said the switches you bought were from an older model, evidently from a RX330.There is an important lesson to be learned from this - do not trust the junkyard people to tell you a part is compatible with your car. DO YOUR OWN RESEARCH before buying a junkyard part or one from e-bay.
/RANT
As for your problem, there is only one fuse for the power seats, a 30 amp fuse labeled P/SEAT in the fuses to the left of the steering column. Do not mistake it with the 20 amp fuse SEAT HTR. How did you check the fuse? Did you just look at it or did you either replace it or check it for continuity? Just looking at these little fuses is not always accurate. Since the P/SEAT fuse also powers the passenger seat, have you tried moving the passenger seat?
Let us know if the passenger seat works so we can have a better idea as to which direction to look.
Well, that's interesting. I got the name from the wiring diagram. I looked my my car, a 2007, and it is the same as yours. There isn't any fuse under the hood with that name, either. Just another example of Toyota/Lexus 3rd rate documentation.
There is a 30 amp fuse in the dash fuses. It is about in the center and has the label TI & TE. I can't put any meaning to that name, so I wonder if it may be the one. I will have to go out to my car and pull it out and see what happens.
I'll be back and update this.
update:
The P/SEAT fuse is on the side of the fuse block. At the end towards the parking brake pedal, look at the side of the fuse block. You will see 2 blue "blocks". These are fuses. The one towards the steering wheel is the P/SEAT. I don't know if it comes out by pulling straight down or by pulling it sideways. In the worst case scenario, it may be held in by a screw. I did not even try to pull mine out as it looks like you will have to remove the lower dash panel trim
Last edited by DennisMik; Jun 29, 2019 at 12:07 PM.
Reason: add/update information
Okay
I think I've found it.
Found a diagram on other site with descriptions: https://bezpieczniki.net/lexus-rx350...zniki-schemat/
It's in polish but no 33 is that seat one.
I took few pictures and it's definitely there. Just looks bit different to those tiny ones. Have a look. Will look for it Monday and exchange it.
I found the same information on another site.n The info I found used different numbers for the fuses. Yours was 33 and mine used 67. Don't know which is correct or if it really matters.
But one thing - the P/SEAT fuse is the one closer to the parking brake pedal, not the steering wheel as I said earlier.
Exchanged the fuse (old looks to be fine btw) but no luck. Both seats are still dead. Tried also to unplug battery for an hour but that didn't help.
What I also discovered is seat heating doesn't work neither. I've checked heating fuse and it's ok. There's also 12V power in the fuse socket.
Any idea where to go next?
The wires from the P/SEAT fuse and the heated seat fuse do not go directly to the switches for the devices. There is a junction block that splits the power to both seats. This junction block is located in the driver's seat. My schematic says "in driver's seat cushion". Plus I don't know how big it is, i.e., how many wires are in it.
Look for some connector under the seat that is wires on both sides of it.
- - - - - - - - - - - - - -
The junction block I referred to DOES NOT split the power to both seats. The split is for the different parts within the driver's seat.
Sorry for the brain fart, guys.
Last edited by DennisMik; Jul 8, 2019 at 12:47 AM.
Reason: correcting incorrect information.
Thanks for that - will look for it in few days when I'm back and will update results.
In the meantime is there any module that controls both: power seat and seat heating?
There are no control modules for the power seats or seat heaters. The junction block I mentioned in the driver's seat is also used for the driver seat heater, but not the passenger seat heater. The wires for the passenger seater do not go to/through the driver seat.
First, I want to correct myself. In post # 8, I said that the power for the seats went to the driver's seat and was split and sent to the passenger seat. This is not correct. Each seat has its own wire going to it from the fuse. This split is accomplished in the fuse panel junction block.
Looking at the wiring diagrams, the wire from the P/SEAT fuse to the driver's seat is a brown wire in pin # O4. For the passenger seat, it is a violet wire in L11. Some people might offer that maybe the ground is bad. Again, each seat has its own ground independent from the other seat. Within the seat, the ground is shared by the positioning motors and the seat heaters.
But I cannot see any connection that would be common to both seats and both seat heaters. The seat motors use one fuse and the seat heaters use another fuse. I will look at this some more and maybe I will see something.
Many thanks for diagrams - will study it closely now.
CORRECTION: heating of both seats does work - I have no idea how come last time I thought it didn't but it definitely does work now. The car has been left untouched for a week and last night when I came back battery was flat and I had to jump start it - not sure if that can have anything to do with whole situation but I'm reporting it in case it could have something in common.
Since both P/SEATS have independent power wiring from the fuse I don't find anything that causes my problem between fuse and seats. I'm going to take the fuse out and check if I have power there. Will update results shortly.
I've tested the fuse and 12v power is there but the brown wire going to the seat seems to be dead (I have 0.03V reading). I believe it's the one the diagram calls "in the cushion" and it's definitely first junction after wires come out the floor. Pic attached.
If I get it right the problem is somewhere after the fuse but before the seats. Is it good idea to try to bypass the fuse and supply 12v directly to that junction with brown wire?
What would you do next?
Seats adjustment stopped working after buttons exchange attempt
