jamisteven

I recently (past 4 months) purchased a used 2006 IS350 and have been slowly sorting out various gremlins, one of the things I cant quite figure out is this heated/cooled seats, after a lot of reading on the topic im still stumped. The problem with it is that regardless of the setting on the heated/cooled controls, it seems to always lightly blow cold air. It can be on hot, blows cool air, on cold, blows cool air. Another thing is that the lights on them, and also the shifter control lights do not work.

Tried replacing the fuse for the heated seats in the drivers side fuse panel, still nothing.

UPDATE: Damn thing was completely unplugged, popped open the center console and both the shifter lighting plug, and heated seats plug were both unplugged. Not sure why I didnt check this to begin with before replacing the fuses

jr4div2

Well I'd say you have two issues.

1. You can tell the heat is on when using the heated seats. They get nice and toasty so you definitely are no getting heat. There's a myriad of harnesses under the seat for all the motors. Could be something has come unplugged related to the seat. Do both seats not heat? That would be interesting. I would think the ***** are a remote control to something that handles the heavier current for the heat. Maybe someone can provide a wiring diagram of the heating coils and how they connect to the car.

2. The fact you can always feel cool air is something many cannot say. Most people cannot feel anything from the cooling fan. And it is just ventilated, not actually cooled. You can put a barrier under the driver's seat rear that will force the cold air from the floor duct, but I find that still to be inadequate.

komobu

In heat mode they should be like an electric blanket. They should heat up, Air should not blow. Sometimes there is an "Open" in the wiring within the seat stopping current flow and they wont work. That is an easy test with an ohm meter.

In Cool mode, a fan should blow air that comes out the small holes in the seat.

2013FSport

iTrader: (2)

^^+5 for the heat side the and ohming the bottom and back coils. Hester coils will have large wires into the cushion vs the motors. These should be be pretty low resistance if measured with an ohm meter. Like 10 to 30 ohms I'd guess?

I'd guess that in a car they use pulse width modulation to control heat as you don't want a rheostat in the dash with 30amps going through it. Meaning a solid state relay turns on DC current to maintain the temp, thus keeping the current flow away from the dial.

An abstract thought is this; your failure mode has the fan on. If there is a circuit that for example knows it is in Cooling mode, perhaps by default it is Disabling the heater.
A schematic would go a long ways. You can buy a two day Toyota subscription to view documents and schematics. It's $15 but I'm waiting for a rainy day...

Ping me if you need help understanding schematic...

jamisteven

Honestly electrical matters are where I am least handy, may need to take it to someone but I dont think its worth it to be honest, really wanted the heated seats for the winter but, ill do without if I have to. Going to take apart the console this weekend and see what I can figure out with a voltage meter and go from there.