Evaporator control not shutting outside air inflow | FerrariChat

Evaporator control not shutting outside air inflow

Discussion in '456/550/575' started by Terence, Apr 5, 2018.

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  1. Terence

    Terence Rookie

    May 13, 2015
    13
    Seoul, South Korea
    Full Name:
    Terence Lim
    When the vent duct ("close") switch is on to shut the outside air inflow, I can still smell and feel the air inflow. What should be done to block the air inflow?
     
  2. Fennicus

    Fennicus Formula Junior

    Apr 10, 2015
    592
    Helsinki, Finland
    Full Name:
    Pekka T.
    H
    Hi,

    Which car? (And MY?)

    I know the 456 GT evaporator now inside out and there are plenty of reasons why the air flaps could get stuck, loose, or not seal properly. And the foam in all the connections and air nozzles tends to age and turn to dust, most likely faster with a lot of sunshine and heat.

    But if you have 550 or 575 it may be a different scenario...
     
  3. tazandjan

    tazandjan Three Time F1 World Champ
    Lifetime Rossa Owner

    Jul 19, 2008
    37,986
    Clarksville, Tennessee
    Full Name:
    Terry H Phillips
    Did not know there was a vent duct switch on the 550.
     
  4. Terence

    Terence Rookie

    May 13, 2015
    13
    Seoul, South Korea
    Full Name:
    Terence Lim
    I have 2001 550. Appreciate any advice.
     
  5. Fennicus

    Fennicus Formula Junior

    Apr 10, 2015
    592
    Helsinki, Finland
    Full Name:
    Pekka T.
    Hi,

    Sorry I don't know the 550 evaporator unit, but the controls look the same as the 456 GT. If the button for inside cabin air recirculation is not pressed in, what happens with the A/C when power is switched on, is that the two servos the top of the unit start to turn the gears and plastic rods push the two flaps down against the unit body. Then resistance makes the A/C ECU cut power to those two servos.

    If the recircutation button is pressed down, the servos turn the gears the other direction and those two flaps tilt/rise until they close against the openings fron the evaporator unit to the ducts of fresh outside air and again with certain resistance the ECU cuts power to the servos.

    Now the unit body, the flaps and the rods are ABS plastic. If the rods brake loose or if the small ends of the flaps the act as hinge pins break, the flaps will be loose (one or both) and then the servos will just keep on rotating the gears until power is switched off.

    This was happening in my car, and it results in a situation where both outside air and air from the A/C unit will freely enter the cabin from inside the dash. The flaps are also covered with foam and some plastic fabric on top of the foam. On mine the foam had also disintegrated. I repleced the foam with new, glued those and the cleaned fabric pieces with 3M upholstery spray glue (very sticky, but so was the original) and now they will go back into the unit. I have also fixed the broken parts with epoxy and some new parts. But I plan not to use the recirculation button either never, or in extreme situations only (like stuck behind a truck in the Gotthardt tunnel).

    So far I think the weakest design considering durability and availability of spare parts and how you can fix broken parts I have found in the 456 GT in the past three years is definately the A/C unit in the cabin. :( I would hope that the 550 and 575 were a bit better, but they may have used the same Italian subcontractor who used the same parts and materials... In 20-25 years the units will start to crumble into bits and I don't have high hopes on Ferrari offering replacement units or any spare parts. I hope I am wrong.
     
  6. Fennicus

    Fennicus Formula Junior

    Apr 10, 2015
    592
    Helsinki, Finland
    Full Name:
    Pekka T.
    Hi,

    Ok, I have those flaps back together and as spare parts availability is almost non existant and prices are high I have fixed and made more parts. One thing that prevents closing the vents is that the original foam seals have turned into dust. I got dark 2mm neopren and cut new seals. Should work well, fortunately the flaps and vents can be taken apart and the two pieces snap back together.

    Cheers!
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    F456M likes this.
  7. Terence

    Terence Rookie

    May 13, 2015
    13
    Seoul, South Korea
    Full Name:
    Terence Lim
    Thanks. I guess the original foam seals have turned into dust.
     
  8. Ozeskiman

    Ozeskiman Karting

    May 15, 2016
    76
    Melbourne
    Full Name:
    Tony
    I have been searching for an answer to a similar issue. I have a 2002 575M. The motor that opens and closes the fresh air recirculation flaps keeps running constantly. It seems that the lever that is connected to it is most likely broken, as described above. However there appears to be no way to get to the motor other than a complete removal of the dash. It is located up near the windscreen but with no access from the engine bay. I've had several mechanics try, including the Melbourne Ferrari dealer. We've even tried to disconnect it from receiving power from the back of the ac controls, but this can't be done. Has anyone any suggestions on how to fix the problem.
     
  9. F456M

    F456M F1 Rookie

    Jan 8, 2010
    3,665
    Oslo
    Full Name:
    Erik
    Try to find out which other cars have the same AC and heat unit and replace it with a new one from the manufacturer or a supplier of (for example) Alfa Romeo parts If that is the one similar to yours. I can not imagine Ferrari 575 is the only car with that box!! They you get everything new. Will last another 20 years or so.
     
  10. Ozeskiman

    Ozeskiman Karting

    May 15, 2016
    76
    Melbourne
    Full Name:
    Tony
    Thanks for the reply. But I'm not sure what you are referring too. The problem I have is the small linkages between the servo motor and the air intake flap that allow the flap to be open or closed. From what we can see ( there is a grill in the section where the windscreen wipers are located that is removable and lets you just see the motor. But no access that we can determine) the linkage is broken and the servo motor just keeps turning. You cannot switch it off. I want to know if it can be accessed without removing the entire dashboard.
     
  11. AVIMAX

    AVIMAX Formula Junior

    Aug 5, 2014
    686
    Toronto
    Full Name:
    Ryan
    Unfortunately, the only way to get access to the recirc doors and their motors and linkage is to remove the evaporator unit from the car. Here are some photos of my unit that was removed and replaced with a used unit. I had an issue with strange noises, the blower motor resistor blew and so the unit was removed and it was discovered that the motor had injected the black covering of the LHS recirc door, and the door had broken off, the hinge part of the door snapped. You can see in the photos, the blower motor and recirc doors are located above the "flange" that mounts the unit inside on the firewall under the windshield. You said you can see the motor from the air intake under the windshield? You should see the 2 connectors above the motor, one for the LHS and one for RHS, maybe you can get something to reach in and unplug the motor that is a problem?

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  12. Fennicus

    Fennicus Formula Junior

    Apr 10, 2015
    592
    Helsinki, Finland
    Full Name:
    Pekka T.
    Hi, the unit itself is different than on the 456 and 456M, but apparently made by the same company out of similar ABS plastic. The recirc doors and their puny plastic rods however also look identical, so perhaps there is a chance to find some spares in some Alfa / Lancia heap of scrapped car parts. It's just very likely they are broken as well. If you can fix the ones you have and renew the seals / foam, i think they should last 5-10 years.

    I have never used a shade on the inside of the car windows before as I have never before felt that I needed one, BUT as I have received some as presents from a friend I have them in the 456 GT trunk and I use them whenever I park the car out in the sunshine. (very rarely :) ). Now that I know how much delicate leather there is in that car and how difficult it can be to replace as well as all that ABS plastic in the A/C unit I am doing my best to avoid excessive heat and all UV rays I can. :)

    Cheers!
     
    JSP likes this.
  13. tazandjan

    tazandjan Three Time F1 World Champ
    Lifetime Rossa Owner

    Jul 19, 2008
    37,986
    Clarksville, Tennessee
    Full Name:
    Terry H Phillips
    Seems like it should be possible to replace some of those broken plastic pieces and links with thin sheet aluminum pieces and metal rods, but it would take a good fabricator and some effort.
     
  14. Fennicus

    Fennicus Formula Junior

    Apr 10, 2015
    592
    Helsinki, Finland
    Full Name:
    Pekka T.
    Hi Taz,

    Sure, and I think it should be fairly easy to fabricate the rods out of aluminum, or even 3D print in ABS, which then would probably not last much longer than the originals. The flaps themselves and the rods could be made easy, I would probably take a metal (steel or alu) rod and use a lathe to make it fit the holes / grooves on the A/C unit and then turn an alu sheet around it, rivet the flap together and perhaps also rivet a connector for the rod. But those rods need to have the "teeth" for the gears of the a/c unit motors. Then just glue the foam / seals and plastic and put them where they belong and test before remounting. I was lucky in that the only broken / missing rods in my case were the simpler ones so i could just substitute those with sheet metal that I cut to fit, drill and used rubber mountings and small setscrews and nylock nuts so it all works fine now. I had the A/C serviced and drier replaced last fall and I have not missed the recirculation at all. :)

    Cheers!
     
  15. tazandjan

    tazandjan Three Time F1 World Champ
    Lifetime Rossa Owner

    Jul 19, 2008
    37,986
    Clarksville, Tennessee
    Full Name:
    Terry H Phillips
    Pekka- Hope you documented that with photos. Would be handy for a bunch of owners.
     
  16. Fennicus

    Fennicus Formula Junior

    Apr 10, 2015
    592
    Helsinki, Finland
    Full Name:
    Pekka T.
    Hi Taz,

    I did. And some of it is in the old threads about the Stereo in the 456 GT and some in the A/C fan control / evaporator threads.

    Also I did get an e-mail from Ross (in the UK?) and sent him a few e-mails and replied also in a private conversation here on fchat, but either my e-mails ended up in spam or he's been unable to respond or be on-line for a while.

    I'll try the search in case I can find those myself. The repaired flaps and seals are already in this thread.
     
  17. Ozeskiman

    Ozeskiman Karting

    May 15, 2016
    76
    Melbourne
    Full Name:
    Tony
    Thanks guys for the answers to my original question about the air re-circulation motor. I've been overseas and just saw the replies. I'll pass this onto my mechanics and see what they say.
     
    Qavion likes this.
  18. Ozeskiman

    Ozeskiman Karting

    May 15, 2016
    76
    Melbourne
    Full Name:
    Tony
    Before I head to the mechanic, I had a look at the location of the aircon unit in the 575. It is located directly behind the engine with pipes attached to it. It looks like you may have to remove the engine to get to it. Can anyone enlighten me on this. Has anyone removed their unit? And if so, how was it done? Thanks again.
     
  19. AVIMAX

    AVIMAX Formula Junior

    Aug 5, 2014
    686
    Toronto
    Full Name:
    Ryan
    I changed my whole unit last year, you cannot get to it from the engine bay, it is inside the car and you have to remove the dash. There are a few things you can access from the sides without removing the dash like the ECU and the heater valve, but if you need to get to the unit, the dash is coming out.
     
  20. Ozeskiman

    Ozeskiman Karting

    May 15, 2016
    76
    Melbourne
    Full Name:
    Tony
    I'm confused now Do you have a 575 or a 456? It seems there are two different answers to my question. I have a 575 and need to get to the motor that opens and closes the air re circulation flap. Fennicus said he had to remove the entire unit from the engine bay. Whereas I thought it was possible via the dash removal option. When I look in the engine bay I can see the unit covered in heat protective foil. So I then assumed Fennicus was correct. But you suggest otherwise. Either way it is time consuming and expensive. My Ferrari dealer quotes around US$2k to get the unit out of the engine bay (and thats without removing the engine, thankfully). To remove the dash is probably cheaper by about half that. But I need to be sure of which is the correct way. Any more thoughts please,
     
  21. AVIMAX

    AVIMAX Formula Junior

    Aug 5, 2014
    686
    Toronto
    Full Name:
    Ryan
    I have a 550, I'm pretty sure the 575 is almost identical. Yes you have to remove the entire unit, but from the cabin, not from the engine bay. The area with foil you are looking at is the firewall and there is no access to the evaporator from there. Check my earlier post, #11 above, I suggested you might be able to get to the wiring for the motor that controls the recirc doors through the air intake at the base of the windshield if you remove the pollen filter. The 2 connectors for the recirc door motors are on the RHS of the unit (at least they are for the 550). I think it's a long shot, but with some creative tools, maybe you can disconnect the motor that is a problem.

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