I have a 2006 lexus is350. One day i tried switching the ac mode from front windshield defroster to regular ac to blow in my face. when i try selecting the mode of the ac it stays on front windshield.
No air whatsoever on either driver or passenger side.
I notice the front defrost button flashing a couple times and it sounds like a whole bunch of shifting and moving behind the dash for 30 sec or so.
Tried finding solutions but no luck,
Ac temp works will get hot or cold, Blower speed works fine as well, Recirculation is fine and the door for it is also not stuck, opens and closes fine with a new cabin air filter.
Even the rear seat vents are getting air out fine.
I've seen 1st gen is300's and older GS models change 1 servo motor on the passenger side by glove box to fix it completely but i am not sure if its the same process for 2is models.
Any help with solution and part number of what i may need would be greatly appreciated.

 

try spraying some deoxit can spray (the red color one) onto the fuse board underneath the steering wheel or front passenger glove compartment and reseat various fuses. Look at the diagram that’s pictured there and focus on reseating the ones relating to the AC.

contact cleaner also works

 

It sounds like your blend door motor might be failing. It could also just be the linkage from the motor to the blend doors. That's what controls where the air blows in the car. The actuator itself could also be the culprit.

 

I will look tomorrow actually i havent had time to but i’ll see if thats my issue, if not I’ll go down the list as well. But thank you for the video i tried looking for similar stuff to my problem before making this thread and found nothing. First time ive seen that video surprisingly. Will make an update tomorrow.

 

Got everything torn down and had a closer look. Blend door is working and not detached like in the video that was sent. 063800-0171 4121 is the first servo motor to be seen which has a bigger looking gear like a half circle, when i change temp hot or cold it moves and appears operational (temp does change).
063800-0171 4132 is the servo behind and slightly above the first one, has a small arm that would move when selecting where i want the air to blow ONLY if temp was set to highest temp but wouldn’t change direction of airflow regardless of it moving as if it worked. However It did NOT move at all when set to lowest temp setting. Maybe thats the culprit? Im still not 100% sure myself even after looking myself. Any more help would be appreciated.

 

having a similar issue, had any luck? if not, have you tried installing any aftermarket head units? I read something about someone frying something by plugging in a bad canbus from a cheap head unit. hopefully that isn't what happened in either of our situations.

 

Sadly no, i still have the issue. I dont want to spend 200+ on servo’s just to see if those are the issues. Been keeping an eye on junk yards so i can pull some but i havent had time for it lately. The mode doesn’t work but car still blows cold and surprisingly works good still. Annoying and would like to fix honestly. If you have a solution/fix in the future please let me know as well. Good luck.

 

Following as I'm having the same issue. Replaced fresh air/recirculate door as that was broken but still wont change out of defrost. AC blows cold/hot no problem.

 

I'd suggest each of you buy a 48 hr subscription to https://techinfo.toyota.com/ and follow their diagnosis / troubleshooting procedures.

Any of you have rodent issues? I'm guessing chewed wires would throw codes, but material trapped breaking things is something else.

 

I wouldn’t doubt if packrats caused my issue but I have no codes stored relating to the issue so I’m wondering if something just seized, although I think it’s a bit too coincidental it happened directly after the screen went black and the main board on the stereo/ac control unit died. Seems like a short of some sort, which would
make packrats seem like a feasible cause. Hoping it’s nothing too serious, although I don’t see any signs of packrat damage anywhere else yet, nor have any other issues appeared.
im trying to source a copy of techstream so I can diag it via the OBD to see if anything relating to it pops up, if not I’m probably gonna take it to the local Lexus dealer for diag when I have some free time. Thanks for the subscription idea, might also give that a try if it doesn’t seem too complicated, although I’m not the best with electrical/reading diagrams