355 climate control - Air direction not working

Hi Guy's,
The air direction knob on the climate control appears to have stopped working. The car now blows air out of every vent with the airflow appearing to be more towards the footwell's. The blower speed knob works fine as does the temp knob. I have also noticed that the air flap to block outside air from entering the cabin has closed. This is even though the button to activate has not been pressed (so technically this should be open not closed).

I have done a power reset but nothing has changed! I have also removed the trunk lining but I cannot see anything obvious.

Is this a common thing? Where should I start looking? All help and advice would be greatly appreciated......

 

I have the same problem. As soon as it gets hot again in Houston I'm taking mine into the shop for them to diagnose it.

 

So these are electrically operated on a 355? Glad my 348 is working but in storage. THe old mechnical cable actuated would be an easy fix. Good luck.

 

Can anyone please help with this? I have searched previous threads but have not found an answer to this.

I'd like to know how to test the actuator without damaging it and how to test the ECU feed to the actuator. This way I can hopefully find the faulty item.

Also interested to know why the air recirculation flap is also perm closed (even with system in stop/off position).

As I have problem with both air direction and also air recirculation flap I'm thinking it's more ECU problem rather than just air direction actuator......?

 

Have you removed the control assembly and taken it apart to verify that the control knob is actually turning the variable resistor? Maybe it has broken inside and isn't connected? If that looks OK I would use a good contact cleaner on the connections and try it again.

Rick

 

Thanks Rick, I've removed the control panel and opened it up via the 4 screws. No issues at all inside. Everything appears to be connected and working properly.
I notice the air direction actuator has 5 wires going to it. I'd like to know how to test this with a voltmeter to determine if it is receiving correct power from the ecu. I could do this without removing the actuator. If the signal from the ecu is good I could eliminate the ecu and purchase a new actuator. Likewise if signal no good I need new ecu.

Input once again greatly appreciated.

 

I've had some wonky behavior with the HVAC in 355s, especially when the battery has been disconnected.

How I've seen this manifest is that there is no air from the face-level vents, even though the selection switch has them activated.

I've been able to solve this in two ways:

1. Press the "Stop" button to turn off A/C, then press it again. Wait a couple of seconds, then air should start flowing through the vents. Doesn't make sense, but somehow the system is getting reset.

2. Disconnect then reconnect battery power if #1 doesn't work. Sometimes the HVAC reset needs this. I saw that you already cut power; try it again a couple more times along with #1.

Eventually things start working fine, once the magic combination is found to reset the HVAC system.

 

You can unscrew the flap actuator motor and see if the output shaft moves, and also pull the connection and test the motor by applying 12v to the leads. I have the same problem that appears to be HVAC ECU or re-set related. The motor moves when I actuate the AC but recycles to the same position independent of the air flow direction setting.

 

Thanks for the info. I really appreciate you taking time out of your work day to assist. I have performed another battery disconnect as directed and this has fixed the flap actuator (air recirculation) issue! This is now operating normally. However the air direction fault is still present. I've also tried the STOP button numerous times with no luck. I'm thinking I should just buy a new air direction actuator unit as its less than $100. Ideally I'd like to test the unit before simply buying a new one but without knowing what voltage should be supplied to any of the 5 wires going to the motor from the ECU. I don't think I can test the unit myself.

Thanks for assistance. Flap actuator fault appears to be solved thanks to another battery reset.
I'd like to test the air direction actuator but it has 5 wires. It appears to be a stepper motor and as such I don't want to start applying 12v to test as I could do some damage if I apply 12v at wrong wires. I think some of the wires are feedback signals for the ecu for it to know the motors position relative to the air openings. If I knew which wires to check feeding the unit from the ECU I could simply test with my voltmeter without even having to remove/disconnect the motor. Without knowing what to test for I might be better simply buying a new actuator?
I also believe that some of the 5 wires going to the actuator could be feedback on the units position to the ECU. If I am correct then the motor could indeed work and rotate but it the unit has in internal fault relating to the feedback position it may not be able to determine its position and this could cause issues for the ECU etc.

 

Hi John,
Both the 355 and 348 are electronically actuated. In fact many people say the 348 system is even worse than the 355 one in terms of reliability. I've owned 2 348's and never had a problem with mine though......

 

Looks like the 355 air direction is done by the same mechanism as the 348, so I can throw out a few ideas. the direction is done by a rolling drum inside the airbox that the actuator turns. It might be worth removing the actuator. Then look at the shape of the drive shaft on the actuator... file down a bolt or chunk of plastic to replicate that shape, slide it into the hole the actuator shaft was in and see if you can spin the drum by hand. With the actuator hanging down, you can try using he air direction buttons and see if the actuator shaft turns. It is a dogger to get to... on your back under the passenger side dash board.
You can get a feel for what's involved on this video I did when I got tired of my car's occasional hiccups... it's a 348, but looking at Ricambi parts site, it seems to be the same set up
[ame=http://www.youtube.com/watch?v=IKjQGPnehjI]Ferrari 348 Climate Control Substitute Part 3 - YouTube[/ame]

 

I'm not saying that the actuator can't fail, because obviously it can.

I've just been down this road before, trying a known working actuator from a different 355, and I had the same results (no air redirection) with both actuators.

Somehow that HVAC unit needs to be reset; it's in the ECU.

 

Thanks guys, I'll remove the actuator and try and test it.

 

Sometimes everything is working electrically but the problem may be mechanical e.g. the plastic piece is broken.
Here is a metal replacement part that you will never have to replace.

PM me if that's your problem
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Image Unavailable, Please Login

 

I think that piece is for the recirculation flap in the front trunk. I think his problem in inside the dash.

 

Thanks guy's,
Yes the front recirculation flap is ok and is now working correctly after the reset. It is the actuator under the dash that is in question. I have ordered a new actuator and expect to get this sometime in the New Year.

I will update once I have received and fitted this.

 

He said Mazda Miata resistor in the video? Nice! I now know I own both of THE correct cars. Thanks!

 

It is a common problem and I think it happens mostly when battery is disconnected and the A/C functions go out of sync. It's happened to me twice, both times after battery shut off. First time I replaced the ECU and then it worked but went out again 1 year later. Replaced with a ECU that I knew worked. Tried everything and could not get it to work, motor defaulted to the defroster vent every time. I manually turned the A/C air selector to have the air come out of the center vents and left it like that. If someone knows how to resync the A/C, I would love to know.

 

How is that done?

 

Remove the motor that controls the air distribution-- held by 2 of 3 screws under the dash.
Have the a/c running and then put a screwdriver into the the hole where the motor fits and turn the screwdriver until you feel air coming out of the center vents and you are done. Tuck the wires that were going into the motor under the dash. I had to resort to doing this after trying for several years to fix the problem. Like I said, I put in a new ECU, new motors, tried a new control panel, nothing stopped the air coming out of the defroster vents

 

I've got my motor removed and have been able to manually rotate the selector to come out the front vents. As soon as I remove the screwdriver it rotates back to defrost or floor vents. Does anyone have any idea what could be causing that?

If I can't get this figured out myself I'll be taking it to my shop and will post their results here.

 

There is a rotating drum that directs the airflow to the vents of choice. When I was doing my modifications, I found the drum spun very easily. I'm guessing that drum isn't computer spun balenced, so when you pull out your screw driver, the drum rotates until the heaviest part is down, and that happens to be where the air comes out where you don't want it. I think you need to keep the screw driveer in the slot and tape it in place, or do something similar to stop it from rotating around on it's own.

 

I believe you are correct. I wedged the a screwdriver under the dash so now I have air coming out the front vents. I ordered a new motor last night. Maybe my old motor was just not able to hold the drum in place.

 

Isn't it fun lying on your back across the door sill, head under dash, with hands stuffed in tight places?

 

I got my new actuator from Ricambi but I'm missing the screws. Does anyone have any idea what size they are?