timmui

Ok, with that part number in the other thread, I was able to find the specs on the motor itself here:
http://dongshunmotor.en.alibaba.com/..._dc_motor.html

I found a mabuchi motor (similar to the ones used in the door locks) that had similar specs, but with some caveats. The dimensions are bigger and it is heavier. However, it draws less current and it has more torque. There appears to be a local company, ie US headquarters, that represents the company in China and offers individual motors. Here is the link: http://www.kysanelectronics.com/Prod...?recordID=2805

Depending on the internal shape of the servo, this motor may be a possible alternative.

Attached are the specs for reference.

salimshah

That is where I was.

Remember to get the 12v version.

I found the physical dim close .. please verify on your own .. but not sure about current and rpm specs as I had nothing to compare with.

If I plan to open mine the next time, it might be worth measuring and comparing exactly. Note: the way the motor sits in the cavity, leaves no margin of error.


Salim

DrDan

Salim, I think we are on the right path. There is no apparent wear and tear on the contact points and there is no visible damage. The only thing the "moves" that can make noise is the motor. I don't know what to make of the fact that the vents work correctly indicating a good motor. Yet how does the motor move without changing the vents? Hmmmm. I will take the unit apart and do a better diagnostic on dimensions etc this weekend.

Dr. Dan

hypervish

I think I recall reading or seeing video where the gear on the servo motor was loose, and that was the cause of the problem. Not the motor itself.

I'm going to be tackling this soon myself, one of my servo motors always becomes noisy during the summer (for the past 2 years, becomes quiet in the winter) presumably because the temp is at the colder side, which I suspect means it is my air mix servo. I will diagnose further when I have some time.

salimshah

Hyper:

There are multiple things that are happening ..
1. Lack of contact between the the contact copper and the track. [cause: wear or contact-grease]
2. Motor brushes worn down. Motor may spin under no load or light load. [Use and end of life.]
3. Wear of the gears ... missing teeth, friction.
4. Actuator arms ... outside servo ... grime and dust require harder force to overcome.
5. Detent spring. They hold the dampers in snapped position

Last time I tinkered with it .. all I needed was to lube the outside spring on the mode servo arm.

It can be one thing or combination. Each case is different.

Salim

theAnnikki

DrDan, your post couldn't have come at a better time. I've heard the infamous "noise under the dash" for probably a year now but was weary to investigate it myself...

A few days ago I heard and discovered a family of mice in my glovebox. They chewed through the plastic housing behind the dash and were building a nest in the air filter area. YUCK.
Since I know the damage that mice can do to a car, I immediately called all the local repair shops but because of the busy weekend, the only place I could go to was Midas.

They discovered a few baby mice and one really large one. Apparently they were all dead... but earlier that morning I found a baby mouse squirming on the passenger side floor. I took care of it before my appointment. Also, I had turned on the A/C and heard a bunch of loud thumps--definitely how I imagine a mouse would sound if it were being thrown around.

At Midas, they disposed of the mice and told me that there was a pretty huge nest. The mice had pretty much torn up the air filter, so of course that was replaced as well.

HOWEVER, a day after my trip to Midas, I heard the weird scratching again. It sounded like the noise that I used to hear, but way way way more mousy. Not sure if I am paranoid or if there might be a survivor somewhere in the system.

Any ideas what I should do? Or any suggestions on places to look within the car that might hold the answer to my question?

If anyone has any advice I would love to hear. Thanks!!!!

DrDan

Follow up on my weekend project.

Sorry to say, I cannot specifically determine what was causing MY scratching noises. However other CL members mentioned that they tried my method and had success. So this is for those of you who are hesitant to get started to give it a try. I need to install the servo now, so I will monitor it in the next few days.

Before you remove the servo, press the vent changing button and watch the cam movement. I believe the cam is in its top most position when the vent is set to “in your face” mode. That is when you want to remove the servo because the cams are finger assessable. I had another post about this procedure that you might want to look at.

Without going through a lot of “Why did you do that?” questions, just accept my advice about removing that 3rd screw first and when you reinstall the servo, replace that 3rd screw last. Also if you have a LED light, use it. A regular shop light will burn your hands working in that cramped space.

Removing the glove box is simple. There are two Phillips screws in the top corners and two 10mm bolts in the bottom corners. Since you will be in the area, have a cabin air filter ready before you start. There are also three spring loaded clip holders that hold the box tightly in place. Two are located about an inch inward from the Phillips screws. The third one is about an inch to the right of dead center. Wiggle the box gently and the clip holders will release. There is a holder for some wires on the top of the box, but it is easily detachable.

The ongoing dilemma is that we all heard the noises. Noises are made by moving parts. But if no parts are in motion, where is the noise coming from? The whole servo is pretty “tight” with close tolerances and therefore not likely to vibrate. My vents change correctly at the push of a button. The motor is held securely in place with “O” ring shock mounts which minimize vibrations. There is no evidence of the motor “stuttering” or searching because the outer cams would vibrate. I am guessing at this point. If all of the mechanical electrical connections are solid, and the motor is seeking or making noises, I would assume that the motor is starting and stopping before any motion can be detected. This suggests to me that the electrical source is randomly fluctuating and it is not the motor. I am sure that the price of a replacement servo has at least three digits between the $ and the decimal point so I will pursue this out of curiosity as long as it is working.

Anyone else out there have any ideas?

Doc Dan

timmui

Wow! A load of detail here. Thanks Dan for going through the effort. Having seen the motor with the measurements you've made, the mabuchi motor I shared is of similar size to the one inside the servo. There's nothing available online that matches the writing on the outside of the original motor though, so we don't know if the specs are the same.

Reviewing the image of the brass piece, I can't be completely certain, but it looks like a gear puller might work that off the shaft.

sylvia

part #c please, I need to order one, where is the best?

Noypi

I need to do this, too. Part # Pls...

westerj

Thanks so much for the picture of the Mode actuator! When I took it apart, I lost the angular orientation. Once i compared mine to the pic, I quickly set the angle of the arm. getting the damper arms back in place took some perspicacity! The issue with the buzzing started from the copper collar having shifted on the electric motor shaft. the dimension of 0.400" from the tip of the shaft to the base of the copper collar had slipped some... just pried it out with a screwdriver and re-established the 0.400 dimension. Works great on final assembly!

dimitrov

OK guys, it's time for my first post and I hope this can be useful to anyone having trouble with the servo motors. I have RX 300 MY2003 and I bought it three weeks ago with the rattling noise in the mode servo. After reading maybe everything in this forum and trying several suggestions - changing, cleaning, lubricating etc. I think I've discovered the source of the noise, and unfortunately it is not caused by the motor itself or the gears or by dirty contact surface. At least not in my case. The cause is wear of the plastic cradles somewhere inside - can be the cradle of the motor, or the cradle of the axes of the gears I didn't have much time to investigate deeply.
The good news is that I found a long term free solution of the problem. I found out that all three motors are exactly the same except its levers. Every motor has two main parts - the "base" which contains the motor and the gears and the contacts and "cover" which holds the contact surface and the lever which moves the flaps.
So I took down both - the faulty air mode motor and the less used motor (the one for the air recirculation) which is located on the top.
I assembly the "base" of the recirculation motor with the "cover" of the air mode motor and mount it as air mode motor.
Next, of course, the "base" of the air mode motor and the "cover" of the recirculation motor and mount it as recirculation motor.
Finally (to my surprise) everything was working like it was coming straight from the factory. No more noises and brilliant operation of all functions of the climate control.

CharBaby

Bought our RX new in 2001. Ours started making noise(sometimes/sometimes not) just after the OE warranty was up. 13 years later, it still makes the same noise...or not!
My SIL bought a Pre-Owned '01 RX in 2004 and her's was making the same noise. Had it fixed only to have it go again shortly after it was installed($150 later).

hypervish

I opened up both my Air Mix Servo and Air Mode Servo today. I moved the collar on the motor up a bit more so that the gear did not move around on the collar. I saw "Froggy" who owns a Lexus IS300 (same servo) on youtube do this and it worked for him.

I'll update this thread once I determine whether or not it is fixed.

BlueCrabby

I just wanted to chime in about how my Lexus dealer solved this constant noise issue
back when my RX300 had this problem. The clicky/grinding noise was constant, as
in it started when I start the RX300 and only stops when I turn off the engine. The
air vent mode still operated correctly.

It must have been a frequent problem that they encountered because as soon as I
started describing the problem, the service adviser immediately knew the part that
needed to be replaced, without even having to consult with the technicians.

Since it was under Lexus original 4-year warranty, it was replaced free and I had no
reason to complain. As soon as I picked up the RX300, the noise was gone.(obviously)

It remained quiet for 2 years and then the exact same noise came back. I went to
another Lexus dealer and they replaced the servo again. This time it was under the
Lexus extended warranty that I bought. Again, everything went quiet after I picked
up the RX300.

6 months before my Lexus extended was about to expire, the noise appeared again..
This time I didn't even bother, but the Lexus technician came up to me in the waiting
lounge and said "your air servo is bad, have you been hearing the noise?" I said
yes and he told me it would be $425 to replace it. I told him that I still had 6 months
left on the Lexus extended warranty. He went to check with the service adviser
who obviously confirmed it. They replaced it for free again. Do these servos go
bad that often for other RX300 drivers?

Anyway.... now my RX300 has been out of factory and extended warranty for a long
time, I just started hearing this noise a week ago. It is the familiar constant noise
that remains on when the engine is running.

Counting the original servo that came from the factory, that's 4 servos gone bad
over the years. It almost feel like Toyota never updated the part to make it more
reliable?

How much $$$ will it cost if I just want to replace the servo with a new or used one?
I read this thread completely and not sure if all the steps apply to me, as it appears
that most people only hear a noise when the vent is actually changing modes.


Thanks in advance!