swtstick

Yes, a clicking sound. I will shop around for a second and third opinion. Good thing is we dont use much heat in SWFL and summer is quickly approching.

matts6887

We dont use much heat here in the southwest in AZ either; but there are a few days here and there in the winter when its cool enough to use it. The one thing i noticed is that when the heat(floor mode) is on; sometimes i have to crank the temp way up to get real heat; whereas opposed to the a/c; I dont have to crank that down very much to get cold air out of the vents. Now awhile back i was thinking of checking mine too but I never got around to it and I figured since its getting to the "hot" time of year here; I probably dont have to worry about til like november or so. So Im not gonna worry about it til then probably. With this said; Im thinking it must be the air mix servo that may be partially on its way out. However; when i ran the diagnostic on it using the auto plus recirculation buttons; I only got a code of 21; but no other codes which is no big deal because I was testing it inside the garage.

rocky5

iTrader: (2)

What are code 12, 21 & 24?

carguy07

https://www.clublexus.com/forums/rx-...f-display.html

cheerio3

I have read through this thread. My heater is not blowing warm air. I removed glove box and can see that my air mix servo arm moves up vertically when I turn the **** to hotter temperatures. My question is does anyone have any ideas as to what the problem may be? I saw someone mentioned a "little door" in the air mix servo not working. If that is the case, the arm would still move and a new servo would solve the problem? I am stumped so far. Thank you.

cheerio3

Update: I unplugged battery as previously suggested by a poster and now my heat does work. I noticed a slow leak coming from the bottom heater core hose when the heat is on a middle or higher setting. Any advice on the leak?

cheerio3

There is a product called Red Angel A/C Sealer. I researched it a little bit. Is there a chance that it would stop that leak at the evaporator hose?

salimshah

Trace the leak to the source and see if there is crack or the camp is loose.

Salim

Mylucy

my dash was replaced a few months ago (04 RX 330) could that be the cause of cold air blowing out on passenger side when heat is on?

salimshah

Welcome to Club Lexus.
The controls are in the dash so there is a chance that it can happen. Some one needs to trace the problem from mix servo backwards and the coolant level in the engine. You may like to post in the right Forum.

Salim

Charlie200

Thank you for the photos and info! Got mine working again.

goomz

Im having issues too. I have codes 33 and 41. 33 is Air Outlet Door Position Sensor Circuit and 41 is Air Mix Door Servomotor Circuit.

Let me begin from the start. I bought the truck in May/June. Did a coolant flush, and bled the system. BUT the air mix servo didnt work. I didnt know this at the time, its summer so i kept it in the cooler temps. So one night its cooler out and i turn the temp dial up for some heat and get nothing but cold air. Which is why i bought a new from the dealer air mix servo. It moves up and down now, where as before it was stuck in the down position for cold air. I plugged it in, reset the ecu. My issue is i only either have HOT air, or ICE cold a/c...no in between. So for example if i set my temp to cold with the a/c on or off, i get cold air. If i turn it to say 76, i get no change in the air temp until i turn it to 84 or 85, then i get HOT air. Could this all be me needing to re bleed the system because the door was in the cold position from when i bled the system? I also am not sure as to why i still get that code, being that the part was replaced and works all the time now?

dalerk

Thanks to all here for the excellent photos and descriptions of the mode and air mix servo motors and how they work. I've previously heard a light "bouncing sound or clicking" coming from under the glove compartment, and about two weeks ago, it went away. Could get AC, but no heat other than car ambient temperature. I followed the advice(s) and found the culprit: defective air mix servo arm getting stuck at the mid-level position between hot and cold.

Tested the servo with the arm disconnecting from the heater/AC arm, and it worked intermittently. Plus the "clicking" sound came back and I could see the servo arm bouncing when activated by the heat/cold **** on the dash. After nearly twenty years of working fine, the servo unit is probably just wearing out. Don't want to go through the process of removing and attempting to repair the unit at this point. A new one will probably last another twenty years.

goomz

I just did the process of buying another assembly, the door mode unit. now, my air does blow as it should on the correct setting of feet, defrost, etc. Also, when I turn the dial from hot to cold, the brand new assembly I replaced a few months ago still goes up and down for the temps. HOWEVER, I am STILL getting codes 41 and 43, 41 Air Mix Door Servomotor Circuit and 43 Air Outlet Door Servomotor Circuit. I pulled the ecu-b fuse for over 30 seconds, reconnected the fuse, re ran the diag and got the same codes. the recirculation assembly above the glove box still opens and closes as normal. I re bled the coolant system (jacked the car up in the front, started the car and waited for the fans to turn on...they did, twice, and topped off as needed, checked the next day and topped off again.)

I am still getting HOT air on the passenger side only and cool to lukewarm hot air on the rear center console vents, and the driver side front/feet as if you split the car in half with an imaginary line, in the middle it seems is what seperates the two temps. There is no dual climate controls. I am thinking a clogged heater core? No smell, no wet interior, no dirty windshield, no lack of coolant. Sometimes ill get hot air from both, and a few mins later the driver side will get cold again. Im at a loss, anybody have any suggestions?

UncleL

I realize I'm replying to a thread from 5 yrs ago but I wanted to ask if this problem was causing overheating? I just noticed the "hampster wheel" noise last week and then I overheated yesterday. I turned my climate control off and on and then turned on heat to HI and the engine temp went down enough to get home (5 min.) I'm just wondering if you all on this thread were more interested in heat and AC for cabin temp or engine temp? Thanks