This weekend the outside temp rose to around 80 degrees. With the sun shining, I decided to turn on the A/C in the front seat. I could hear a fan running, but no air was flowing thu it. As I changed fan speeds on the seat, the fan (motor appears to be in the dash below the CD changer) changes speed. However, no air is coming thru. I think there might be something blocking the air.

Does anyone know a good way to diagonose and possible fix this problem without going to the stealership? My LS is outside of the warrenty.

 

More info needed, I'm not quite familiar with the AC system...but specifically is there no air coming out of any of the vents? The car also has temperature gauges, supposedly in the front seatbelt buckles, that adjust air flow accordingly. Were you using the dual-zone climate control? Did the oscillating vents turn on or were activated?

If there is specifically something wrong with the motor...hmmm it may need to be replaced. I wonder about the AC filter as well, but that's likely some other issue.

 

I have noticed the same thing with my 05 LS.

What I have noticed, is when it gets really hot the seat A/C just doesn't work very well.

Have you tried turning it on at night and see if it still doesn't work???

 

it doesnt work like a fan. its more like cooling coils to me. after a short while my seats give a cooling sensation. feels great coming out of the gym.

 

digial_b is correct. Yoiu don't feel cold air being blown, you feel a cool sensation and the seat cushions (bottom and rear) get cool. I originally thought there was an issue with mine because I expected cold air and checked with my dealer who told me how it should work. It is the same with the heat.

I checked it on another randomly selected LS from the lot and it worked exactly as mine did.

 

I have the same problem, also on a black / black 2005 Ultra. I had the regional Technical Specialist from NJ check them last week while he was here in Baltimore to solve my horrendous ride quality problem (repalced all 4 wheel height sensors). He described the seat cooling / heating system to me, and I found the website of the company that supplies Lexus and ALL other companies that offer environmentally controlled (heated AND COOLD) seats. The site is www.amerigon.com if you are interested.

The eat cooling switch needs to be activated within 10 minutes of the ignition, and the vehicle automaticlly resets the control to 50% power ater 15 minutes, so if it ain't cool by 15, it ain't going to be.


NOTE that the servcie manual says that the front seats won't cool at all if the rear seat or seats are set to heat.


The Techniical Specialist told me that the thermostat setting for cooling is factory set at 89 degrees which sounds pretty high to me for a cooling system, but tehn th body is at 98.6 and 89 shoulkd tend to seam cool as a result.

The Peltier element in each seat heating/cooling module (2 per seat - one in bottom cusion, one in seat back) opperates by reversing the current to the module. One direction generates heat at the semiconductor junction, the other direction results in cooling of the semiconductor junction. Each module has an integral fan unit that forces the heated or cooled air through channels molded into the seat foam to ultimately discharge through the perforated leather seat material.

I, like you, do not believe that my seats cool AT ALL above 80 to 82 degrees, and I tested that theory with a hand held Infrared temperature detector over a thiry minute period during an 88 degree day in September. At the start of the test, all interior temperures measured 95 degrees. With the exception of the drivers seat, all other interior surfaces (passengers seat and seatback, passengers door panel, and rear passengers side seat back) all approached the A/C space temperature set point of 75 degrees during the test period, while the front of the drivers seat cusion between my legs where the air flow would not be blocked (but was also exposed to the general cooling tendancy of the car's space A/C system) never dropped below 91 degrees. The drivers seat back never dropped below 94 degrees, and the seat cusion below my left leg never dropped below the initial 95 degree measurement. The drivers seat was the only one that was set to cool (MAX setting) during the test. Even with this test data, I have been told that the seats are per spec, because the Tech Specialist measured the resistance at the switch, resistance of the wire harness to the seat, heating/cooling module fan operation, and the voltage and resistance of the Peltier element itself. All measurements were in acccordance with the Lexus service manual. Seats must therefore be working correctly, right?.

NOT!

My 2002 LS430 Ultra had heated / cooled front seats, and they cooled to the point that I had to move the control off the MAX setting because they got TOO cold. The Pertier module used in these seats were obtained from the same source (Amerigon) in 2002, but the element itself was changed in 2004, and this may be causing the apparant lack of cooling problem.

I am comforted that someone else is having exactly the same observation as me. That means that we're BOTH crazy.

Good luck. Please post any change in your situatioin if you ever find a solution.

 

Thanks PJARDIEU Great info. I have a 2004 Ultra and my seats get HOT but not cold enough to notice a change. You did mention "The seat cooling switch needs to be activated within 10 minutes of the ignition, and the vehicle automatically resets the control to 50% power ater 15 minutes, so if it ain't cool by 15, it ain't going to be." Are you refering to the two seat control ***** on the center console? I always leave mine to max cold in the summer for all the good it does.

 

Yes. Those are the switches that I'm talking about. Like you, I usually leave mine in the full cool position in the summer. When I had the 2002 LX430, they seemed to keep on cooling all the time. It's possible that the ramping back to 50% "feature" is a control system change implemented when they changed the Peltier system in 2004. I believe that the 2002 system used both the normal Air Conditioner fan for the whole car as well as the fan in each Peltier module, thereby providing significantly more air flow and better/faster cooling. If this belief is correct, there may be no way to fix what appears to be insufficient or no cooling in the new arrangement. Lexus told me that they changed the system partly because a lot of their customers didn't have the A/C system for the car on when they tried to cool the seats, and with the initial system both fans HAD to be in operation or the system wouldn't work. With the new system using only the fan in each module, this would no longer be the case. Too bad the one fan that is being used now isn't big enough.

I have also emailed the manufacturer of the climate controlled seat unit to see if they have a known fix to this problem, and will post any response that I receive back from them.

 

I have a 2001 with the ventilated seats i can feel it sometimes but its mostly hard to notice. I think its normal. They also dont make it too cold because of condesation and that would cause mold in the foam of the seats.

 

On my 2001 ls 430 ultra I found the hose coming from the blower housing to the seat off of its proper place letting the air go under the seat instead of thru the seat!





42FLOYD

 

DD....does your LS have "tiptronic" shifter? I have an 01 ultra and mine does not have the same gate that yours does...

 

That's the late-model gate. Perhaps DD just linked that photo to show the seat temp controls (not a photo of the 2001 model car indicated in his signature).

FWIW, my 2003 seems to blow cold at times and not so much at other times. I think the main AC fan has to be crankin' for the seats to do much of anything, but if it is, I can clearly feel cool air coming out of the seat perforations.

 

There is an intake filter at the base of the front of the seat that can be changed. Just a thought.

 

Man, you guys are good! This is not an actual photo of my LS430. I just used the temp controls to show what I was referring to. I don't have the sequential transmission on my LS. Its a shame too. My GS400 had it and was fun to used every once in a while