SalSegav

Hi all!

On my 2003 GX 470 w/ 135,000 I have an issue that I can't figure out how to resolve.

The driver side lets out hot heat and the passenger side lets out cold air. I have the dual climate control and both sides are at MAX HEAT with the blower on HIGH.

I have 2 vents for each the passenger and the driver.

The left side of steering wheel vent is allowing max heat. the right side of steering wheel vent lets out warm air. Not as hot as left side but warm. On the passenger side, its only letting out cold air and gets colder if I lower the temp on the climate control for right side.

Engine coolant is full, no lights on dash. Blower motor sounds like its working fine.

Any thoughts??

thanks.

ROSCOGX470

Not sure but is there blend doors in the GX? Sounds like the heat isn't flowing through the passengers side. Try shutting off the dual zone and see if the same temp heat come through all vents

rj4510

I bet you have a bad servo in the climate control. If you take the glove box out, you'll see three electrical connections attaching to either white or black plastic parts, to the left, under the navi unit. You can see what appear to be arms on I believe two of them. As you change temps, you should be able to see or feel all three moving to adjust the air mixture. The one that feels like it's clicking or not moving at all should be the culprit.

They are about 150 to 200 each to change and, if you got as far as being able to detect the broken one, you can change it easy enough. Based on your description, you may have two bad ones, but I'd start with the one you detect on the passenger side and see how it goes. I'm pretty sure there's a servo motor on the driver's side as well...if I remember correctly.

I just about blew my stack when I found out the price of these things. Not that this helps the pain any, but the model numbers are the same for some Toyota models as well, so they are not exclusive Lexus part numbers. You may get lucky and find a used one.

Let us know what you find.

Mparent

I saw a thread in the forum that said you can try to take the servo apart and clean the grease and contacts. I am gonna if that helps mine before shelling out the $$. Mike

LexusDude1

Did you ever resolve the problem? Was it the servo?

SalSegav

kind of sort of

the servos work. I took apart the dash and see the little armatures moving with the temp change from dash.

what significantly helped was putting the correct radiator fluid in. I was using a no name brand from local auto parts store.

when I switched to the Toyota brand I got hot heat from driver side. And ok heat from passenger side.

thanks guys !

IanB2

Sounds like a clogged up heater core, possibly due to mixing incompatible coolant. With dual zone climate control, there's 2 sides to the heater core, making it possible to have heat on one side and no heat on the other, depending on where the blockage is.

chiph9

Please don't say the other fluid was Dex-Cool -- That stuff causes more disasters.

https://grassrootsmotorsports.com/fo.../141875/page1/

Chip H.

parm

bad air servo motor

jjohnson13

my driver side servo did not move with changing the temperature. I am looking for a replacement part and found a reasonably priced one but I'm not sure if the driver side part is different from the passenger side? I would assume they are different parts but I couldn't find different ones online. Anyone know where i can find replacement part for driver side servo motor? or is there somewhere I could purchase just the dc motor that is inside the servo? i have an 04 es330

Lexus4321

The servos, with DIY info, I believe is posted on this forum, Search for them.