Technical Climate control mistery

[tomicdd]

Hi guys,
I've changed recirculate actuator last Saturday with working used one. After diagnostics I've got the same errors like before change. Left mixer has dead motor and I'm planing to change it soon. But, my control unit start to be crazy - sometimes it won't operate windshield flap, sometimes operates only windshield motor regardless button presses, sometimes reports short circuit, sometimes reports right mixer and above all it won't replay to proxy alignment request. I've checked recirculate flap and it's stuck closed, regardless error delete and unit test and selflearn. Looks like Control unit didn't detect proper current of motor and it broke a lever again.
SO, any thots? Also, alfaobd reports potentiometer voltage 3,6V if I recall, should it be 5V?
And when it's full nuts unit reports additional heater error (which I don't think that I have)
Thanks

 

[PuntoHowTo]

Dash board earth issue perhaps ? These sorts of issue are very difficult to diagnose

 

[tomicdd]

Couldn't say, I have to remove all dashboard again. Maybe control unit is faulty or some wires have lost isolation...

 

[tomicdd]

Proxy alinement procedure could say about unit internal electronics problem?

 

[BogdanGeorge]

Hi. If you didn t sort it out, try to clean the climatronic control panel ( magneti marelli). Read , my post, i know you have some actuator problems but try to clean it. If it doesn t work, test and buy a used climatronic panel. Good luck.

 

[thenerko]

My ac is snapping plastic parts of motors even after cleaning and replacing their potentiometer multiple times followed by MES calibration. And always reporting error "signal low" on multiple motors. I have noticed that my ac unit screen is flickering especially of you look to display from bottom. I would appreciate if someone says is this normal, suspecting that ac unit is faulty or has ground problem.

 

[tomicdd]

So, we can say that operating voltage of potentiometer is 5v for reference voltage. In my case, alfaobd shows 3,7v. This can be because of faulty hvac node, short circuit of actuator or cabling/ground. This weekend I'll dismantle all, again, and replace recirculation, left mixer and windshield actuator. Maybe hvac nod also. I'll measure all voltage. One pin from. Nod, 17, should have 5v and I think that is potentiometer reference voltage.
Did anyone replace all cabling in hvac unit? What about grounding?
Does hvac node produce this 5v or it is received from engine ecu?

 

[thenerko]

So, we can say that operating voltage of potentiometer is 5v for reference voltage. In my case, alfaobd shows 3,7v. This can be because of faulty hvac node, short circuit of actuator or cabling/ground. This weekend I'll dismantle all, again, and replace recirculation, left mixer and windshield actuator. Maybe hvac nod also. I'll measure all voltage. One pin from. Nod, 17, should have 5v and I think that is potentiometer reference voltage.
Did anyone replace all cabling in hvac unit? What about grounding?
Does hvac node produce this 5v or it is received from engine ecu?

Sir, just wanted to ask, did you solved problem?

 

[tomicdd]

Sir, just wanted to ask, did you solved problem?

Hi, I have replaced complete hvac node and left mixer actuator and proxy aliment has passed and all but recirculation works. Still shows like open circuit to recirculator and in spring all replace all cabling. Also I've checked grounding wire for hvac and was fine. Potentiometer still shoes 3,7v but it works just fine.
Most likely hvac node was faulty also. I have had some issues with old one with max fan speed. Now it's flawless.