Technical Brava 100 16V, Clima air mixing actuator problem

[NickBr]

I have a problem with the operation of the motor that moves the flap for the air conditioning air mixture as I write in the title.

Fiat code for this is 46723615 and on it i can read Bosch VMC 180200 1 (07) 0 132 801 124 1 Made in Malaysia 905

Some time ago the error CLI began to appear on the odometer display, and the cooling did not work.
The air conditioning compressor was running normally but I had no internal cooling.
Looking for it I discovered that the flap that chooses hot or cold air depending on the position of the temperature selector rotary switch was responsible.

So I removed this motor and after checking the movement of the flap I saw that it moves easily and normally without getting stuck at some point in its rotational path.

Inside the plastic box of the motor there is a motor and a potentiometer that is probably to check the position of the flap.

I powered the motor with a voltage of 12 volts and saw that it moves properly without a problem, I also threw contact spray on the potentiometer, which also changes ohmically depending on the movement of the shaft.

Now I have to remove the motor from the air conditioning box and turning the rotary temperature selector to turn it to the hot or cold position depending on the weather, and then remove the connector so that the valve remains in this position and I fasten it that way.

If I place it normally and connect it, it will stick either in the hot position or in the cold position.
When I operate the motor out of position it operates normally in both directions.

I have no problem ordering a new motor, but I do not know if the problem is in it or in the air conditioning control unit and where this unit is.

Can you help me ?

 

[Neverth]

What was the code it was throwing in the dash? You can get the code again by putting it on Hi temp and Max DEF, blower to zero, ignition on and cycle 0-auto two times leaving it 0.

Might as well be the internal temperature sensor being broken so it has no idea if to heat or cool the cabin. Or the temperature pot.
Code 65 for mixture actuator.


Even faulty PWM (fan speed) unit will cause the system temperature to be stuck (bought ELX marea with this fault in the winter and it was stuck on cool after I just wired power directly to the blower motor, no response to the temperature knob). So it is kinda pain in the ass.

My HLX marea occasionally trows error cli (once in couple months) but works fine so I jsut ignore it. I've replaced the recirculator actuator with RC Servo on it as the original one had eaten its gears (it has no sensors, just opens and closes fixed time with stall of motor stopping it)

 

[NickBr]

What was the code it was throwing in the dash? You can get the code again by putting it on Hi temp and Max DEF, blower to zero, ignition on and cycle 0-auto two times leaving it 0.

Can you please write all this in steps ?

Thnx

PS: some times the blower motor comes on with everything closed, now i remember that.

 

[Neverth]

Ignition off.
Put temp to Hi and direction to Max DEF, blower to zero.
Ignition on and on blower speed knob:

0 - auto - 0 - auto - 0.

If I remember right, I can try tomorrow morning if I remember to do so.

 

[NickBr]

Finally the fault is from the air mixing motor (46723615) which is controlled by the interior thermostat because the car has auto clima.
The motor while rotating normally when it reaches the end of its rotation from both ends does not stop. I removed it and cleaned it because inside it has a potentiometer that states its position but still does not work.

Also now I have a problem with the motor that moves the diaphragm of incoming or recycled indoor air.
The problem started when I heard a banging sound when I pressed the air selector. Until finally the diaphragm was stopped in the middle of its path. Trying to move with my hand but without exerting too much force I could not make it work. But when I press the muton for a few seconds, the motor sounds that it works but then stops. Because I do not know what the problem is and I do not operate it so as not to destroy it.
While searching I found that its data is ELECTRIC MOTOR 46722197 and made by Denso woory GZ1T300201

, but I have two problems. Firstly it is in a position only 1 cm away from the side metal panel, and secondly I can not find it to buy it. I post a photo of it to help. From what I understand, the entire heating / cooling system needs to be removed in order to make any repairs.

 

[NickBr]

And one more thing, I have found the whole heating system new with code 735257475 in a good price but it does not match my chassis number,

Φωτογραφίες αγγελίας με κωδικό PT1426545

Φωτογραφίες αγγελίας με κωδικό PT1426545

www.ix.gr

the code for my VIN is 735249456.

Do you know where or how I can get spare parts?
Because the code 735249456 costs about 600 euros new spare part and this is half the price of the sale value of the car.

 

[Neverth]

If you look into the second newest post in "Instument Cluster backlight" you can see we had discussion on it. Seems like on yours the potentiometer has broken in it or the sensing for it is broken in the controller as it still drives the motor. Can you measure the 3-wires to the pot to see the control unit feeds voltage to it and it gets correctly shown with the ratio shown in the workshop manual picture for full hot/cold?

As for the recirculation banging, sounds same as what happened to me: broken gear. The recirculation just has motor and it is driven one direction or another with timer. It should stall once flap reaches end, but gear gets weak and it will break and then go to end and skip teeth. I've replaced mine with RC servo while dash in place and it took bit of time due to the space issues.

 

[NickBr]

Neverth,​

​

Thanks for your reply .

So far I have removed and measured with a multimeter the potentiometer readings on the hot / cold motor. Giving voltage correctly and inversely I made the motor turn in both directions while at the same time measuring the ohmic resistance in the potentiometer. The resistance varied depending on the axis rotation but I can not say if it was correct because I do not have the book to compare the measurements.

So far I have removed and measured with a multimeter the potentiometer readings on the hot / cold motor. Giving voltage correctly and inversely I made the motor turn in both directions while at the same time measuring the ohmic resistance in the potentiometer. The resistance varied depending on the axis rotation but I can not say if it was correct because I do not have the book to compare the measurements.

For the recirculation ,
from what I have seen the motor is fastened with three Phillips screws, one is easy to remove but the rest very difficult, but even to remove it I will not be able to pull it because it will definitely have to move as much as the length of the shaft. Am I making a wrong assessment?
I would like to describe how you managed to replace this motor with a rc servo, but also what tools you used to remove it because this seems impossible to me, or did you use the same plastic box and just change the internal mechanism?

The motor is this iside (the photos is not mine)

And the space i have to work for it is this:

 

[Neverth]

Here is spec on the mixing motor, it is just ratio of the resistance (voltage between output/input when powered). So you can try feeding 5v to the +- of the pot and then measure the output voltage, measuring resistance doesnt tell if the pot can actually carry current/voltage. Max heat would be about 0.707*5v= ~3.5v and min would be 0.26*5v = ~1.3v. So if you can measure proper voltage out of it between while it rotates, set it to the max heat, set flap to max heat and install and hope for best? I'd measure in/out voltage once connected to check it if there is problem with the feed.

As for the recirculation, I think I broke the last one? Here is pic of the motor glued with epoxy to the original output arm in the housing.
You can unclip it from the metal bar you see in the picture.

 

[NickBr]

Thanks for the info, but how do I measure voltages at the potentiometer terminals when it has no electrical connection to the motor voltage? may be powered by the control center.
I will try to build an electrical extension to measure voltages while the motor is running.

If I can unclip the motor from this metallic silver surface then I may have solved my problem.
I have no problem removing all the parts of the car that I need to access the heating system, but because the car is old, in a month it will become 22 years old and has 165,000km, any mistake or damage by mistake to something else may be fatal for repair.

Did you unclip the motor too? All this time I was wondering how they put this motor in such a difficult position, I could not believe it.

Thank you very much .

Tomorrow morning I will replace the abs unit because I have been driving with the light on the last two months.
I have checked the wiring and the wheel sensors up to the connector, I hope I can do it.
If the abs that has saved me twice from an accident works and I consider it of primary importance then I will continue in the heating system.

 

[Neverth]

If you got bench power supply, you could use it to power the motor and potentiometer, but extension cable also works and you can also measure the voltage it feeds to the pot.

The heating unit is preassembled before installing so space issues for motor replacements are not that important, and it has lasted 20 years so far, Ive seen mechanical cable driven ones break as the cable wears on older pickups.

I don't remember what I did, it was long time ago and I just remember removing glovebox, the seat and laying on my back there, it took time to unscrew as I think i used a loose hex bit and fingers. I got 280 000km on the 20v hlx weekend.

As for ABS unit, it was a common problem with the lucas unit so there is guide for fixing the power feed: https://www.fiatforum.com/guides/how-to-repair-abs-central-unit.312/

I got the bosch without rear mechanical load distribution valve so it works fine. Also I remember one forum user having abs light and we told him to just go to a field and brake a lot as there was air in the system or something as normal driving it had not engaged in ages, using it cleared it up.

 

[NickBr]

Yes i have a bench switching power supply 0-50V - 0-50A, i think it is enough

The biggest problem I face right now is the removal of the motor, after that to proceed to a solution is now easier, so at least I think.

I will come back with more when I have already started work.

 

[NickBr]

I opened a new topic for abs here:

Brava '2000 100/16v Abs problem | FIAT Bravo / Brava

I own a Brava 100 16V and I have a problem with xxx, a few months ago the yellow warning light of ABS turned on a few times for a while and then went out. It has been permanently on for the last month. The anti-lock braking system does not work, I have checked it in panic braking and the wheels...

www.fiatforum.com