Mondial 8 AC Troubleshooting | FerrariChat

Mondial 8 AC Troubleshooting

Discussion in 'Mondial' started by swong46, Aug 7, 2019.

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  1. swong46

    swong46 Karting

    Jun 24, 2015
    137
    Bay Area, CA
    Hi all, got my A/C recharged and it was working but since stopped. They put UV dye in there but so far, I don't see any leaks. Haven't checked the condenser yet. There is dye at the tip of the low side fill port but that is probably just from filling.

    I just bought a manifold tester to check the pressures. When the car is on, there is 11.XX volts at the compressor, not 12. It spins fine when I apply power directly to it but still not cool. Must just be a leak...

    The manual says that the rightmost cold air temperature thermostatic rotary switch controls the compressor clutch. The pipe coming out of it looks ok but I just don't trust it! Could there be an issue with this switch if I am getting some but not enough voltage to the compressor?

    Lastly, the water electrovalve works with the manual hot/cold lever but I see another copper coloured pipe coming out but is broken. What is this? Attached a photo.

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  2. Wade

    Wade Three Time F1 World Champ
    Owner

    Mar 31, 2006
    32,793
    East Central, FL
    Full Name:
    Wade O.
    For the life of me I can't recall the name of that sensing "thingy". But you need it. Fortunately the valves are available and not expensive either.

    https://www.ebay.com/itm/Ferrari-Mondial-Heater-Valve-60929900-/110837665225
    https://www.ricambiamerica.com/car-diagrams/ferrari/v6-v8/mondial-group/mondial-8/heating-system/60929900-water-valve.html

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  3. swong46

    swong46 Karting

    Jun 24, 2015
    137
    Bay Area, CA
    Thanks! What does it do? Measures air temp inside the black box plenum? Is there a way to bypass whatever this thing is doing?
     
  4. Wade

    Wade Three Time F1 World Champ
    Owner

    Mar 31, 2006
    32,793
    East Central, FL
    Full Name:
    Wade O.
    Why bypass it? When was the last time the coolant system was flushed? Two birds? ;)
     
  5. swong46

    swong46 Karting

    Jun 24, 2015
    137
    Bay Area, CA
    I flushed the heck out of it about 2yrs ago. Just curious because I am not sure what it does or what benefit I will get by getting a new one vs bypassing it.
     
  6. Wade

    Wade Three Time F1 World Champ
    Owner

    Mar 31, 2006
    32,793
    East Central, FL
    Full Name:
    Wade O.
    The manual says yearly, but I can't tell you what happens with others' cars.

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    So, its a great time to do both. Btw, if you want the a/c to work then every component needs to work as well.
     
  7. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,828
    Isle of man- uk
    What pressures are you getting with the test rig- with the compressor off the suction and discharge pressures will be the same. When the magnetic clutch engaged the compressor the suction pressure will drop and the discharge pressure will rise. If you can put your fingers on the 2 pipes from the compressor, one will be warm or hot and the other(suction) should be cool.
    The voltage at the magnetic clutch should be 12 volts.
    Is the magnetic clutch engaging ?
     
  8. swong46

    swong46 Karting

    Jun 24, 2015
    137
    Bay Area, CA
    I will check the pressures over the weekend. The compressor is getting 11.xx volts so not engaging. It engages and spins properly when I apply 12v from the battery directly.

    So I wonder if the cold air temperature switch is affecting this? Maybe it thinks it is already cold so it's not supplying full power to the compressor. In the manual it says it controls the clutch, old school feedback loop? I just can't find information on what these thermostatic switches and valves actually do!
     
  9. Wade

    Wade Three Time F1 World Champ
    Owner

    Mar 31, 2006
    32,793
    East Central, FL
    Full Name:
    Wade O.
    Section H of the Mondial 8 Workshop Manual is for the HVAC system. It has just about all of the info you and your a/c tech needs.

    I believe Paul has a download site if you don't have it already.

    https://www.ferrarichat.com/forum/members/paulchua.145512/
     
  10. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,828
    Isle of man- uk
    If
    you are getting 11 volts and it is not engaging the clutch , then you need to find out why you are losing the full 12 volts. As you have 11 volts then the control system is working fine. Somewhere you have a poor connection and suffering a voltage loss.
    Since the clutch engages with a 12 volt supply then that proves the clutch electrics, just need to find the reason for the loss of volts
     
  11. swong46

    swong46 Karting

    Jun 24, 2015
    137
    Bay Area, CA
    I agree, though, with the clutch engaging, it still does not get cold.
     
  12. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,828
    Isle of man- uk
    You need to get the volts sorted first, in case the clutch is slipping and you are not getting the full compressor output.
    Looking at the fuse/ relay box. Bottom row and 3rd relay in from the left is the supply to the compressor clutch. See what the volts are out from the relay.
     
  13. swong46

    swong46 Karting

    Jun 24, 2015
    137
    Bay Area, CA
    Recharged the system back to normal high and low pressures. Clutch now engages and disengages like expected, not sure if it's just not that cold or still not working. The amber AC light used to turn on but not anymore.
     
  14. Alden

    Alden F1 Rookie
    Rossa Subscribed

    Apr 25, 2010
    2,903
    Central Florida
    Check to make sure you have the correct R-12 pressures at 2500 RPM, per the factory manual, not at idle, like most cars.
    Alden
     
  15. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,828
    Isle of man- uk
    With the compressor clutch engaged, put your hands on both connections coming from the compressor- is one cool and the other warm/hot. If you have a noticeable difference in temp then the compressor is working.
     
  16. swong46

    swong46 Karting

    Jun 24, 2015
    137
    Bay Area, CA
    Yeah, low side was warm and the high side burned my finger...
     
  17. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,828
    Isle of man- uk
    So that means it is compressing the gas ok. Now put your hands on both pipes on the drier in the boot space ( i think you call it a trunk for some odd reason) the inlet and outlet should be the same temperature and be cool- same as outside air temp.
    If you found that the outlet pipe was cooler than the inlet( can be a lot colder in extreme case) then your drier is getting dirty and needs renewing.
    The liquid refrigerant from the condenser goes through the drier, this has a metal screen on the inlet to stop any dirt, the silica jell beads absorb any water vapour to stop icing up of the expansion valve.
    When the drier gets dirty , it becomes partly blocked and the liquid refrid suffers a pressure drop between inlet and outlet- this causes some of the liquid to turn to gas and its temp drops, hence the outlet is colder than the inlet- think of letting a CO2 fire extinguisher off- the icing is the co2 going from high pressure to atmospheric pressure.
     
  18. swong46

    swong46 Karting

    Jun 24, 2015
    137
    Bay Area, CA
    Inlet and outlet feel the same, but warm. Took it for a long drive today to Monterey and it blew cold the whole time. Maybe not as cold as I remember though. AC light never turned on.
     
  19. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,828
    Isle of man- uk
    In that case the drier is fine-the temperature of these pipes is limited by the outside air temp which is the cooling to the condenser.
    The AC light must be a bulb failure as the compressor is working.
    Other thing to look at is the air flaps - does it allow you to select outside or recirc air ?
     

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