456M Climate Control HVAC shot | FerrariChat

456M Climate Control HVAC shot

Discussion in '456/550/575' started by 2000 456M, May 15, 2008.

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  1. 2000 456M

    2000 456M F1 World Champ

    Sep 29, 2007
    12,600
    Portland, OR
    Full Name:
    Allan
    I was just told by RTGT that my climate control panel had a sticking relay that was sending voltage constantly to my HVAC fan motor and that was causing the fuse to blow. Only solution: $2,600 replacement (P&L). Anybody had this problem before? Know where I might be able to get my hands on a used one?
     
  2. oss117

    oss117 F1 Rookie

    Jan 26, 2006
    4,185
    Plantation, Florida
    Full Name:
    Alfredo
    The price they have quoted you is for the control panel only or for the whole job?
    If it is for the whole job it is not too bad in my opinion, as changing the blower motor is a *****.
    The control panel on the other hand, is a one minute job, as it pops right out of the console, but there again, I would not recommend you opt for a used one, as you do not know what you are getting and you my get some other problems.
    You may want to check Ricambi America's prices for comparison anyway.
     
  3. 2000 456M

    2000 456M F1 World Champ

    Sep 29, 2007
    12,600
    Portland, OR
    Full Name:
    Allan
    Thanks, I did check with Ricambi--the part was $1960 or thereabouts. It was just the control panel which I realize is plug n play. Problem is that it took them a long time to diagnose the problem as to why the HVAC fan fuse was blowing (they took the central console apart I was told), so there was a lot of sunk cost already. If I supplied the part they said it would be $700-800 and they wouldn't be able to guarantee it. It did seem pretty steep to me but I gave them the go-ahead because I realized that any incremental savings I could make would be more than offset by the time and aggravation factor.
     
  4. F456 V12

    F456 V12 F1 Rookie
    Silver Subscribed

    Mar 13, 2004
    4,730
    Coto de Caza
    Full Name:
    Christian
    I had a similar problem with my 95 456GT and the problem was the A/C clutch was drawing too much current and blowing the fuse. What fixed my problem was a new "Sanden" A/C compressor for about $400 I went to an independent shop and he asked me, " do you want the unit which says Ferrari for $2,400, or the same unit which says Sanden for $400." Easy choice for me.

    In any event while trying to do some trouble shooting, I popped off the control unit, about one minute and took it apart. In layman's terms, this control console is about, $5 dollars in components and 10 dollars in plastic. This is a very basic two layer board, through hole technology and hand assembled. It is powered by a very simple data bus and driven by an 8 bit uController interface. The problem is not in the controller, it is down stream in the system. There is no direct connection to a 40A fuse from that panel, voltage does not trip a fuse - current does and your problem is likely a metal on metal short, A/C relay control or a problem like I had.

    You are being ripped off in my opinion.

    MB
     
  5. 2000 456M

    2000 456M F1 World Champ

    Sep 29, 2007
    12,600
    Portland, OR
    Full Name:
    Allan
    If the problem is as you described, and I understand you correctly (doubtful, since I'm not a die hard techie), replacing the control panel won't fix the problem, only a new A/C compressor will. RTGT (the authorized Ferrari dealer in Portland) did the diagnostic work and concluded that it was the panel, an approximately $2K item. They've got a pretty good rep among the chatters in the Northwest group, and ultimately I have to rely on someone. I haven't seen stories about RTGT service ripping off the members, but I certainly was not a happy camper when I learned how much I'd get nicked.
     
  6. F456 V12

    F456 V12 F1 Rookie
    Silver Subscribed

    Mar 13, 2004
    4,730
    Coto de Caza
    Full Name:
    Christian
    I could be wrong, but all the controller does is tell other things what to do and it is done in logic (sending bits). There is no wiring harness and if I recall it has a 9 pin data connector and a two wire power connector. Mostly likely under the dash there is an interface which connects to the high current circuits which control the A/C. All I'm saying is if it is just the controller in the center console, way too much $$ for labor and parts. If it includes underdash/underhood stuff, that may be reasonable.

    Go ahead and buy the controller, but have an agreement that if the problem still exists you can get your money back...see how confident they are in the diagnosis

    MB
     
  7. oss117

    oss117 F1 Rookie

    Jan 26, 2006
    4,185
    Plantation, Florida
    Full Name:
    Alfredo
    Allan, in my previous msg I had stated the controller is an esy swap, but the blower motor is a different animal (and that is true for every car).
    So you should clarify what is it that they are going to do for you for the price they have quoted you.
     
  8. 2000 456M

    2000 456M F1 World Champ

    Sep 29, 2007
    12,600
    Portland, OR
    Full Name:
    Allan
    #8 2000 456M, May 19, 2008
    Last edited: May 19, 2008
    I spoke with RTGT service this morning. The a/c compressor was the first thing that RTGT checked. They also fixed a few wires and only then went on to the control panel. Apparently a switch relay under a button was sticking even when the button itself was in the release position and was sending a constant current causing the small 15 amp fuse to heat up and blow. Make sense?
     
  9. Fennicus

    Fennicus Formula Junior

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

    A very old thread, but relevant for me, unfortunately.

    My HVAC had been neglected for many years and had been full of water occasionally etc. I sorted out the drain tubes etc. and it mostly worked fine although in the beginning (three years ago) it would occasionally either just blow full speed or nothing, but then it worked just fine for more than two years. Oxidized contacts, lack of use etc. I thought.

    But now, this fall, in late August it just stopped working at anything but full speed. The automatic mode etc. all work fine, it blows cold or warm depending on the setting, but only if I either switch it on max power or manually turn the fan to speed setting "4".

    This is a familiar problem for me from the Jaguar forums on many, many Jaguars between 1987 and 2009, where the resistor or "control switch" for the fan or fans on the HVAC system has died. For those there is a simple fix of either purchasing new spare parts for a nominal amount of money, or even replacing components on the control switch itself, like a resistor that has died.

    I have tried to locate a similar item in the 456 GT schematic, workshop manual and spare part catalogue. The only thing I can find is this:

    Ferrari Part #63934500

    Fits: Ferrari 456 GTA (from Eurospares website)

    #63934500: ELECTRONIC CONTROL STATION
    - Valid till Ass. Nr. 20878

    £1,804.41 Each

    Now maybe to some of you that is not a problem, but for me £1800 GBP plus VAT and shipping is a lot of money!

    Ok, I could just buy a second hand unit, but that would then eventually also fail some day, right?
    (and it's only "half price," that is still over £900 GBP plus VAT and shipping anyways.)

    Are there really no other components that control the fan/fans of the HVAC unit? It's all built in that unit?

    Anybody aware of companies fixing those "control stations" or anyone with DIY experience on that particular "control station"?

    I am not an electronics whizz kid, but I can hold a soldering iron and/or replace chips, ROM's and diodes.

    Cheers,

    Pekka T.
    Fin.
     
  10. stevegtsi

    stevegtsi Formula Junior

    Feb 21, 2004
    316
    i had a similar problem on my 550. its a relatively inexpensive part. i don't have the part number but can find it if you need it-its not the climate control switch.





     
  11. stevegtsi

    stevegtsi Formula Junior

    Feb 21, 2004
    316
    i believe its part 64280200, also used on the 456. if you check the parts interchange thread there may be a less expensive alternative. good luck.



     
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  12. Fennicus

    Fennicus Formula Junior

    Apr 10, 2015
    592
    Helsinki, Finland
    Full Name:
    Pekka T.
    Ahhh, great, thank you!

    I thought there should be something like this, but could not find it myself. I will try to get one and locate it in the car. :)

    And even from Eurospares:
    NEW
    To Order
    Subject to Availability
    £147.41 Each

    Much much better than £1800 GBP. Cheers!
     
  13. stevegtsi

    stevegtsi Formula Junior

    Feb 21, 2004
    316
    glad this worked out. good luck with it.




     
  14. Fennicus

    Fennicus Formula Junior

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

    It did not work out yet, I am about to order lots of spare parts, I basically have everything but the dash and AC out of the interior (and the dash will go too) as I can not budge this "electro blower regulator." I have the wires loose, I have the screw from the bottom out, and it moves, but will not come out.

    Are there any other screws or straps or something that keep it there? It's in a very tight spot to say the least, I have moved most of the wiring out a bit and I think there should be enough room to get it out, but something at the top seems to keep it hanging there.... :eek:

    arrgghhhh....

    Pekka T.
    Fin.
     
  15. cls

    cls Formula 3

    Jun 12, 2007
    1,663
    Los Angeles/Montreal
    Full Name:
    Chris
    Use a little silicon grease on the hose in front of it. It will slide out.
    FYI, I can't remember exactly, but I think it's one screw.
     
  16. Fennicus

    Fennicus Formula Junior

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

    Thanks, yes, the spare parts catalogue also shows only one screw, so it must be just that hose that keeps pushing it in from the top. I'll try with some lube and more wiggling...

    Cheers,

    Pekka t.
    Fin.
     
  17. Fennicus

    Fennicus Formula Junior

    Apr 10, 2015
    592
    Helsinki, Finland
    Full Name:
    Pekka T.
    #17 Fennicus, Mar 11, 2018
    Last edited: Mar 11, 2018
    Hi,

    An update, or two.

    Now that I have the dash out I could (just & just) get to the upper screw of this blower regulator thingy. Yes, on mine (early 1995 Japanese market car) that thing has two screws, one in the bottom and one at the top. I know the WSM and parts book only shows one screw at the bottom.

    Image Unavailable, Please Login Image Unavailable, Please Login

    But again, now that I could see one rod missing and the recirculating flaps loose, I tested the unit, and again everything works except the top and recirculating flaps are loose.

    Which brings me to yet another question I could not figure out from the WSM nor the logic graphs: what is supposed to stop the two motors controllng the recirculating flaps?

    Now that mine are loose, they just keep on rolling slowly whenever power is on. Regardless of mode or even swiched off!

    They keep on rotating "down" in all situationa, except if I press the "closed circulation" button on the HVAC panel and then they reverse direction, which is normal, but they never stop!

    I can not locate any sensors for them, so friction only?

    I think on mine either the connections to the plastic flaps broke off or the motors or control for those flaps started to malfunction and thus broke the connections to the rods.

    How could I stop those motors from operating? Just unplug them and leave the flaps close in the lower position? (I have no need for them really as it never gets that hot in here)

    Cheers!
     
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  18. Fennicus

    Fennicus Formula Junior

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

    Quoting myself. I was able to figure this one out, although with the condition of the black plastic casing (and my car apparently has seen very little heat and sunshine!) I am seriously thinking of jamming the recirculating flaps shut with some black Sikaflex.

    I was able to put back in a glued flap with the gear and rod and it works. It seems the A/C ECU controls all servos with some value for resistance, which is basically good, as it will not break things if something jams. But the bad news is, that every time the unit is powered on (and that happens when ever the ignition switch is turned, regardless if A/C is switched on or not!) the servos get power and "try" to move the flaps. Normally they just push a bit and then the ECU switches them off. BUT if the casing gives in, or once one of the rod ends or flap ends snaps off, it will continue to "push" until the geared rod drops out and then the servo will be turning as long as ignition is switched on. :(

    Quite honestly I have seen a few solutions for this kind of sports car A/C and heating, and the one in the 456 GT is a nightmare waiting to happen! You can not get spare parts, it is pretty much impossible to fix, as the black plastic starts to crumble no screws will stick anymore and the rods and hinges and flaps will all become loose and then the unit will make these sad mechanical noises whenever you have it switched on.

    I sure hope they had something better in the 550 and 575, or you will be next!

    There was a spare from a wrecked car of e-bay, for €2500 euros. And there is no guarantee it will not crumble to pieces in a few years... :(

    I think I will also find out if the motors (6 and 7 IIRC) can just be unplugged and the A/C would otherwise work normally. I think so. Or then just jam the flaps shut (so the blower only takes oitside air) and hope that the rods for the flaps will not break on their own...

    Cheers!
     
  19. Fennicus

    Fennicus Formula Junior

    Apr 10, 2015
    592
    Helsinki, Finland
    Full Name:
    Pekka T.
    #19 Fennicus, Jan 25, 2020
    Last edited: Jan 25, 2020
    Hi,

    By popular demand, here is an update with pictures on what I did.

    It's very hard to take pics in there as the whole A/C unit is so crammed in there.

    Here you have a look at the A/C evaporator unit without the RH side flap for closing the recirculation opening vs the fresh air intake form the RH side of the cabin.

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    And here you can see the feeds for motors nr 6 and 7 cut, again they are in the RH side footwell, next to the A/C unit:

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    I used normal connectors (male & female to connect them back, so I could have the motors push the flaps close with the rods:

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    As you can see here, now the flap tightly seals the opening from the A/C evaporator unit to the cabin (for recirculation of air), so now I un-plugged the connectors I had added to the feeds for motors nr 6 and 7 and thus they no longer try to push the rods any further when the A/C ECU is powered up, like they normally do until they meet enough resistance. Thus now in my car if one pushes the recirculate button the A/C ´control panel, these flaps do not open either (and close the fresh air intake) but I like it that way, two summers have gone and I was happy with the HVAC unit working this way. :)

    Oh, to the top left in that pic you see the arm/rod connected to the large flap for the center air vents in the dash, that rod was missing, so I substituted it with something simple I made:

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    Like this:

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    The small tape roll is just jammed there to support the pieces of ABS plastic I glued back to their places with some ABS glue I bought from an industrial plastic/rubber wholesales company (ETRA / Etola in Finland)

    The rod is just a piece of sheet metal cut into that shape, two holes drilled and rubber vibrations mountings put through the holes (to avoid noise and vibration) and small metric setscrews with nylock nuts. Now also that flap works the way it's designed and the glassfibre panels and carpets covered this up with the center console. So I think problem solved in my case for many, many years I hope! :)

    Cheers!
     
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  20. tazandjan

    tazandjan Three Time F1 World Champ
    Lifetime Rossa Owner

    Jul 19, 2008
    37,986
    Clarksville, Tennessee
    Full Name:
    Terry H Phillips
    Pekka- Very nice and undoubtedly helpful to future owners and techs. Recirc is not used all that often anyway. On most cars here, Max AC does shut the outside outlets to speed up cooling in the cabin, but no such setting for Maranellos, where you would have to do it manually.
     
  21. Fennicus

    Fennicus Formula Junior

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

    Updating an old thread, as also, despite that I thought I had fixed this for good, I had to revisit this place last winter.

    It turned out there actually was nothing wrong with my original resistor pack / fan speed switch, but (as you can see from the old photos) the main power and ground connectors were oxidized and somewhat burnt, which probably resulted in the replacement (I have been told these are all NLA, so keep you old ones and someone can surely open them and renew the resistors and thus repair this switch / controller) going bust, last summer it started to also only blow on max speed or nothing. :(

    So the old switch is back all connectors thoroughly cleaned with a relay connector cleaning product and HVAC works fine, I still have the recirculation disabled, I don't need it.

    That's how I supported the dash as I did not want to take it completely out, of course I did have to go through (again) unfastening all the nuts and bolts and instrument panels etc. Thank God I don't have airbags. :D

    Cheers!






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