AIR CON Not Working

    Car: 1999 840 Ci Sport. Travelling in heavy rain, aircon working fine. Stopped at motorway toll booth and opened window to pay toll. When I closed the window the car steamed up completely. It took ages to get the windows clear, with heating and de-mist on full. Now the aircon isn't working. I have had it re-gassed (had lost about 30% gas since last year but it is kept stationary over the winter). I've checked the fuses - all OK. I notice that the aircon clutch is not engaging, hence compressor (fitted new last year), is not being activated.


    Can anyone tell me what triggers the aircon compressor clutch? Any ideas what has gone wrong?


    Thanks

    Nr Welshpool, Powys, Wales[INDENT]E31 840 Ci Sport - 1999
    VW Passat Alltrack - 2013
    Mercedes SLK 320 - 2002
    Toyota Rav4 - 1997[/INDENT]

    There is a switch in the system checking the pressure. If the pressure is too low (loss of gas) it won't activate the clutch. This switch (64 53 8 390 815) is located directly at the drying container.
    Another option for the malfunction is a defective "sword" which is the brain of the AC system. Part number is 64 11 8 367 838


    Switch:
    http://static.bmwfans.info/images/epc/MTQ2NzlfcA==.png


    AC control unit
    http://static.bmwfans.info/images/epc/ODY2MV9w.png

    Probably again low on refrigerant. More likely since you had observed a previous loss.
    Self help: buy bottle, refill.
    Timm had a how to on his page and as far as I remember also here.
    It sure is cheaper than replacing all the bits and bobs that may be leaking the gas although it´s actually nice to have a system holding charge for 10 years or so ;)


    Reinhard

    Zitat von anguswolfendale;120632

    Thank you Wokke,
    Let's hope it is the safety pressure switch!



    I actually don't suspect the switch but as Reinhard mentioned low refrigerant.
    Since you already experienced a slight loss and especially the condenser likes to go as it is made from aluminium and pressure is up to 20 bar in the system.....
    I guess you know what I mean.
    If you decide to go for a refill and don't want to do it yourself choose a company that fills the system with CO2 first with up to 10 bar and then checks for leaks.
    I made myself a set of special adapters with normal car valves so I can just fill compressed air into the system for a pressure check. Quite handy if you have to do it on more than just one car.

    I had it refilled, thinking that was the original problem, but it is still not working despite the recharge. Ah well, wheel off and a dig into the wheel arch to check the pressure switch - maybe a loose wire, says he hoping!

    Nr Welshpool, Powys, Wales[INDENT]E31 840 Ci Sport - 1999
    VW Passat Alltrack - 2013
    Mercedes SLK 320 - 2002
    Toyota Rav4 - 1997[/INDENT]

    check if there is 12v on aircon clutch, if yes , the clutch has died....
    if no , then check the pressure sensor/ fuses

    840cia E31
    740ia E38
    M5 E34 3.6 individual
    730ia V8 E32
    525tds E39 ( pour madame)

    Looks like it is the clutch. I can move the centre part of the clutch which is fixed on the drive of the compressor, so I presume the compressor is not seized. I've checked that there is a 12v supply to the compressor/clutch connector although this is present even if the aircon is switched off on the heater controls. That's the limit of my problem diagnosis given time and resources so it's booked into the Stealers on Thursday - will update on outcome.

    Nr Welshpool, Powys, Wales[INDENT]E31 840 Ci Sport - 1999
    VW Passat Alltrack - 2013
    Mercedes SLK 320 - 2002
    Toyota Rav4 - 1997[/INDENT]

    Got th ecar back from Rybrooks BMW - fault: Insufficient gas in the system and too much oil in the compressor, inhibiting its movement!! Inspection, pressure check, re-gas and test: £253.80 inc VAT:banghead:.

    Nr Welshpool, Powys, Wales[INDENT]E31 840 Ci Sport - 1999
    VW Passat Alltrack - 2013
    Mercedes SLK 320 - 2002
    Toyota Rav4 - 1997[/INDENT]

    wow, that ain't cheap. Can you at least trust them? Too much oil sounds a bit strange to me since those filling stations do everything automatically.
    I just had it done on my '91 850i and all the mechanic did was type in the car model and push the START button.
    And if there was too much oil in the system preventing the compressor from moving:
    1. How come it worked at the beginning?
    2. The compressor clutch must be dead by now because if the clutch engages and the compressor internals don't move....


    I can't help, but I'm a bit confused.

    Hi Wokke,
    I contacted the dealership again to challenge what I had been told. The BMW "technician" said that the specification is for the E31 compressor is 33 - 35ml of oil to be in the compressor. He found 175ml of oil in it, which had caused a hydraulic "lock-up" preventing the compressor from turning. He thought that the original problem had been a drop in refrigerant pressure, causing the pressure switch to stop the aircon working to protect the compressor. The local garage had then re-gassed it and their machine states that they should add 110% of the oil drained from the system (I've checked this with them). They had drained 158ml out so added 175ml. They thought that 35ml seemed very low.


    Can anyone verify that 33-35ml is the correct volume of oil for our compressors?

    Nr Welshpool, Powys, Wales[INDENT]E31 840 Ci Sport - 1999
    VW Passat Alltrack - 2013
    Mercedes SLK 320 - 2002
    Toyota Rav4 - 1997[/INDENT]

Jetzt mitmachen!

Sie haben noch kein Benutzerkonto auf unserer Seite? Registrieren Sie sich kostenlos und nehmen Sie an unserer Community teil!

Benutzerkonto erstellen Anmelden