sherryjean

Please help. I just bought a 2010 Lexus RX 450h. The fan in the passenger seat(for ventilation) comes on automatically at startup , even when the controls are set to off.
I'm pretty sure it kicks back off sometime during my ride, what is causing this? Is there away to just disable the fan in the passenger seat?

Clutchless

I think you may need to replace the heated ventilated seat control switch. This happened to someone on the HS250h forum. Here is a link to that thread, or you can have a shop replace it for you. https://www.clublexus.com/forums/hs-...e-control.html

Or you could find the fan wire under the seat and disconnect it.

sherryjean

Thank you for the reply. I think I'm gonna try to unplug fan wire under seat if I can find it then!

vlad_a

Just in case, be sure to keep clear of the yellow wire loom. Those are airbag wires.

sherryjean

Thanks for that valuable info because I prob would have pulled those. I disconnected the one that was closest to the back of the seat and that wasn't it, and I am staying away from the yellow. Does anyone know which one it would be? Would it be closer to the front of the seat?

703

Does the led for the fan switch come on? If not then it's just disconnected and the fan stays on. You can open the dash cover for the transmission reach in and connect the the connector.

Is this an imported car from Japan ?

sherryjean

Yes the Led lights work and when I turn it on and even on high, the fan goes on high like it supposed too. But then I turn it back to off and (the light goes off) and the fan is still running at a low speed. I can put it over on heat and the fan is still running also. My driver seat is perfect and does just what it supposed to do?

703

Ok it may not be the wire harness then since signal is getting to the motor. Could be a faulty switch which is not registering off.

mcomer

Are you sure you are not hearing the fans for the Hybrid battery that is under the back seat?
The three (3) vents that are at the rear passengers ankles create a bit of fan noise.
When you sort this one out be certain that you do not block the vents with towels or
blankets. The batteries make heat both charging and discharging.

sherryjean

It's for sure the fan in the seat and it is blowing out the seat :-(

Clutchless

Based on your comments and diagnostic tests it appears to me that you have a defective cooling/heating seat switch that needs to be replaced. There are a couple on eBay for $65, I would get and have a local shop install it (not the dealer) http://www.ebay.com/itm/2010-2012-LEXUS-RX350-HEATED-SEAT-SWITCH-POWER-CONTROL-X709-/182490937244?fits=Model%3ARX350&hash=item2a7d4eb79c:g:YZEAAOSw32lYycSb&vxp=mtr

http://www.ebay.com/itm/RX350-2010-SEAT-HEAT-COOLING-SWITCH-453451-613539-/322455398671?hash=item4b13d6e90f:g:TjIAAOSwsW9YzD5h&vxp=mtr

sherryjean

Thanks so much for your help! I am gonna try this. I think its an easy install too.

stevecrx

Hi 703, I have a similar problem. The seat ventilator fan is always on and the switch light is off. Rotating the switch from heat, cool and 0 does nothing to change the fan speed. I turned off the AC, but it continues to be on. Can you elaborate what you mean connecting the connector in the dash cover?

Thanks!

Clutchless

As discussed in the thread above, you need to replace the seat fan switch or switches and they are located on the center console (described as the dash cover) (you know where they are) that is all he meant. If you want to turn it off right away you can pull out the switch and disconnect the wires or pull the wires under the seat. You may be able to reach the wires by reaching in through the center console storage hole after you remove the 2 boxes inside it. There is secret compartment underneath (great for stashing stuff like wallets while at the gym etc). Maybe you can get to the seat fan switch wires that way. Otherwise, you have to pry up the plastic piece with the switches to get at them. I think the links above will help as all Lexus vehicles have the same switch.

Just do not touch any yellow wires (especially under the seat) as they are for the airbag system!

If still unsure, buy the switch on eBay and have a local repair shop or body shop install it for you as they will be much cheaper than a dealer.

skssf

FYI...if the J45 connector to the seat heater switch gets disconnected (as Lexus of Marin kindly did and forgot to reconnect on our IS250) while servicing something else in the car, then you'll notice the following (at least for vehicles with that use the 84751-30180 seat heater switch):

• none of the seat switch lights (orange for heat, green for cool) will come on
• the seat fan blower will be on continuously