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My A/C quit working on my F430

Discussion in '360/430' started by whatheheck, Apr 25, 2018.

  1. Snapshift

    Snapshift Karting
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    May 31, 2020
    203
    Centralia IL
    Full Name:
    Lyle D. Pahnke
    I am in the exact same position. F430. Last summer a/c was fine worked great. This summer , inop. nothing changed. Bought the expensive r134a canister with a digital gauge on it and hooked it up to low side pressure schrader valve forward one. Zero reading on suction side with a/c running for 10 min. Charged up to 35 psi in green for ambient temp. Still no cold air. Compressor not running at all. Took about 1/2 can of refrigerant. Used a ThinkDiag tool that can single out a/c relay and clutch and activate it, I hear relay click but no clutch engagement. My question is also what could be wrong? Should I continue to add more refrigerant thinking it is still low in charge, and possibly risk overfilling it, or maybe it is still undercharged and once compressor pressure switch senses enough pressure on high side, it will turn on compressor and reduce suction pressure as it compresses the refrigerant and increase the high side pressure. Fuses and relays all check out, just no compressor clutch engaging. Discussed with my indy and itll go in next week for its annual. Maybe can figure out something by then. Help.
     
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  3. Qavion

    Qavion F1 Veteran
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    Feb 20, 2015
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    Ian Riddell
    Does the tool tell you how it is activating the relay? Is it talking to the HVAC ECU or the engine ECU?


    Relays clicking are generally a good sign that the relay solenoid is operating, but interchanging it with a known good relay is a better option. If we knew how the tool was operating the relay, it would tell us which parts of the system are operating correctly. Assuming we don't know how, we'll have to break up the circuit and check each part.

    Here's a simplified diagram of the compressor control circuit...

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    I'm working on a more comprehensive diagram, but it's probably best to keep the circuit simple. As a first step, you could pull the compressor relay PSR1 and check for 12 volts power on pin 30. If you have power, you could jumper pins 30 and 87 and this would activate the compressor clutch directly. You can do this with the ignition off as the jumper is putting live battery power on the compressor clutch (as the relay does during normal operation). You could get someone to listen for the clutch engaging. Use a suitably sized jumper wire (it may get quite warm if you don't)

    If this works, and assuming a clunking clutch is a good sign, then it's a relay control issue.

    Pressure switches have been known to fail, so you could pull the plug on the pressure switches and jumper out pins 2 and 5 to simulate pressure ok. If you have trouble identifying the pins, the wires going to pins 2 and 5 should be blue (with white stripe) and orange (with white stripe) respectively.

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    Note that I'm using some rather dodgy OEM wiring diagrams with lots of mistakes in them but this should be correct :D
     
  4. Snapshift

    Snapshift Karting
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    May 31, 2020
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    Centralia IL
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    Lyle D. Pahnke
    #53 Snapshift, May 4, 2021
    Last edited: May 4, 2021
     
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  5. jag-oo-r

    jag-oo-r Formula Junior

    May 27, 2015
    387
    This is GREAT stuff! Thank you! With this and what Flash32 gave us, we should be able to get to the bottom of the issue.
    I'll dive into it this week and report back.

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  6. mike32

    mike32 F1 Rookie

    May 13, 2016
    3,654
    Uk
    You are introducing gas on the Lp side but the low pressure switch is on the high pressure side after the compressor and the condenser. It is in the high pressure liquid line by the drier and before the expansion valve. You need to short out the LP switch to get the compressor clutch to engage.
     
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  8. jag-oo-r

    jag-oo-r Formula Junior

    May 27, 2015
    387
    So, I don't see anything about pressure in the data streams. But, see attached photos.

    When I toggle the a/c switch on the dash, the status changes to off appropriately. When I push it back to "out/on", the "request" switches to "on" immediately, and the "compressor"follows a second later.

    However I cannot toggle the compressor relay from the x431. It gives me the fault you see below.
    Image Unavailable, Please Login Image Unavailable, Please Login

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  9. jag-oo-r

    jag-oo-r Formula Junior

    May 27, 2015
    387
    When I push the a/c button to "out/on", I can feel the relay pull (I've got my hand on it). Nevertheless, I swapped it for a known good relay. No change.

    I think at this stage I need to get a look at the clutch and see if it's engaged.

    Is it accessible through the cabin? Or easier from underneath? I still haven't had the cabin access open. How tough is that on the spider?

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  10. Way2fast

    Way2fast Formula 3

    May 24, 2006
    2,117
    Santa Barbara County
    Full Name:
    Sam
    I wasn't getting any cold in low. If I wanted heat, it was super hot if only one notch up from LO.
    Dealer just ordered this valve Image Unavailable, Please Login

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  11. flash32

    flash32 F1 Rookie

    Aug 22, 2008
    2,827
    Central NJ
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    Dominick
    Based on all the things you did do far .looks like a compressor /clutch issue or wiring to the compressor

    Get underneath ..remove undertray and get your multimeter probe light out to test plug on compressor

    That will confirm what your issue is



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  13. jag-oo-r

    jag-oo-r Formula Junior

    May 27, 2015
    387
    Yup. That's where I'm headed next. It's a shame that Ferrari complicated the process by providing a jack point that is encircled by the undertray..... so; place Jacks, up, remove screws. Down. Remove jacks, remove undertray. Replace jacks, then back up.
    Reverse is just as complicated.

    I keep thinking there's gotta be a way to simplify that. Y'know?

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  14. Qavion

    Qavion F1 Veteran
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    Feb 20, 2015
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    Interesting. Looks like X431 is telling the engine ECU to command the compressor on, so at least it's checking the wiring from the ECU to the compressor relay coil.

    I don't know how it knows what the compressor is doing. There is no feedback circuit shown in the wiring diagram.

    You couldn't hear any clicks from the clutch itself in a quiet garage with the jumper wire?
     
  15. mike32

    mike32 F1 Rookie

    May 13, 2016
    3,654
    Uk
    When you get under the car it is easy to take the aux belt off, you can check pulley rotates, then hook up a 12 volt supply to pull the clutch in.
     
  16. grtoz

    grtoz Karting

    Dec 14, 2010
    126
    Byron Bay, Australia
    Full Name:
    Graeme Towers
    There is. Race Ramps 10in wheel cribs. Jack up one side and place the cribs. Do the same on the other side. No need for further jacking unless you want to work on the brakes or suspension. Image Unavailable, Please Login

    Sent from my SM-G955F using FerrariChat.com mobile app
     
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  17. mike32

    mike32 F1 Rookie

    May 13, 2016
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    What are they made off ?
     
  18. Qavion

    Qavion F1 Veteran
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    I have their ramps. Lightweight and strong, but I wouldn't really recommend the ramps. Kinda expensive, especially if you buy the extenders for better nose clearance. They are impractical for oil changes.

    Is it safe to jack up the car 10 inches on one side?
     
  19. mike32

    mike32 F1 Rookie

    May 13, 2016
    3,654
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    I jack mine up 8 inch but in 4 inch stages, then use 4x8 sections of railway sleepers from local garden centre. Good enough to get under it and work
     
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  20. jag-oo-r

    jag-oo-r Formula Junior

    May 27, 2015
    387
    Well.... a new and meaningful (if confusing) detail:
    This evening I took the car for a drive. As usual, I started the car and let it warm for 10 minutes or so. When I got in the car, it was FREEZING inside. The dash was reading 84d (d) ambient, top up, windows up, etc. The A/C was COLD. It was set to auto/LO/hi (controls left to right). I turned the fan to auto, then I backed out of the garage, put the top down, and headed out for a drive, feeling quite satisfied, haha. But by the time I got to the first stop light, the a/c was no longer cold. No combination of controls could return the cold air. Ambient temp this evening was roughly 65d (f).

    So what do we know? Well, the compressor works.



    Any ideas here?
    Does this job any thoughts or ideas?

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  21. Qavion

    Qavion F1 Veteran
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    There could still be a problem with your compressor. Maybe "freezing" is a sign that the system pressure is too high. One of the pressure switches on the receiver dryer is an overpressure switch (28 bar) which removes power from the clutch. Maybe the compressor isn't controlling the pressure properly. I don't think the overpressure switch is latched, so I guess it would simply reset when you switched the system off and on again.

    Was the system regassed? I've lost track of who did what. I dont know if the compressor is designed to compensate (to some extent) for system overcharging? Again, jumpering the pressure switches will bypass this safeguard, but will possibly prove that it's a pressure-related problem if your AC cools for more than 10 minutes.

    No doubt there will be lots of other reasons for this behaviour.
     
  22. Qavion

    Qavion F1 Veteran
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    Feb 20, 2015
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    Sorry, missed this. So you're saying the indication was wrong? The outside air temperature sensor on the driver's mirror is used both for HVAC temperature control and for dash indication. I'm just not sure how the system combines the data from this and the "dozens" of other temperature sensors.
     
  23. flash32

    flash32 F1 Rookie

    Aug 22, 2008
    2,827
    Central NJ
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    Dominick
    These are the items that could be going wrong
    Bad expansion valve causing freezing in evap and causing a blockage
    Bad clutch/coil on compressor
    Fans not running on condenser

    I would still like to hear that the compressor is engaged when you lose A/C - maybe clutch gets warm and gives out - also internally.. the pressure controlled plates may be faulty ( less likely if good for a while)

    I think a little listening for changes in noise ( fan on, compressor engaged will get you closer)
    At one point .. need to start using gauges and voltmeters
     
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  24. jag-oo-r

    jag-oo-r Formula Junior

    May 27, 2015
    387
    Thank you, all of you, for your suggestions and help. I haven't really had a chance to dig into it fully yet: there a lot going on, haha. It's racing season......, and it seems I'm always working on the race car. Plus it's landscaping season.... and it seems I'm always working on the landscaping. And I still work for a living..... and it seems I'm always.... well, you get the idea.

    I doubt I'll be able to spend much time on it this weekend, either, being mother's day and all the kids coming home for that.

    Hopefully towards the end of next week I'll get some more time.
    Again: thank you all!

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  25. mike32

    mike32 F1 Rookie

    May 13, 2016
    3,654
    Uk
    The compressor does not control the pressure, it just compresses the gas as it received it. If it has a high suction due to the expansion valve being full open then it will have a high discharge pressure.
    Best to find the hot gas line from the compressor discharge at the condenser inlet, then check the outlet to see if it has lost heat in the condenser ( should be about outside air temp plus about 5C at the outlet)
    Now find the drier and check if any difference between inlet and outlet temp with your hands. It should be same temp- if the outlet is cooler then drier is getting blocked and the liquid freon is expanding over it.
     
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  26. Snapshift

    Snapshift Karting
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    May 31, 2020
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    Centralia IL
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    Lyle D. Pahnke

    Well I jumped the compressor relay and I barely heard a click. I put on my high and low pressure gauges and had a can of refrigerant connected and lines were purged beforehand. l let it run with the jumper on the compressor relay terminals and added more refrigerant. It still had what I had put in a few days ago but was way undercharged. This time with the jumpered relay (presumably compressor running)it took a full charge and the high pressure increased to about 145 for the ambient of 68F and 25 on the low side. However, I didn't get much if any cold air out of the vents 58F is what was coming out of the vents. Replaced the A/C Compressor relay and checked all fuses all good. I guess Ill drive it on a warmer day and see if it puts out any cold air but at least its charged. It must have a pretty severe leak to have had zero static refrigerant pressure when I started, but at least by the pressures the compressor seems to be working. Why no cold air is beyond me, at this point.
     
  27. mike32

    mike32 F1 Rookie

    May 13, 2016
    3,654
    Uk
    The fact that the compressor has 25 on the low side and 145 on the discharge side shows the compressor is working. Adding the fridge gas is fine provided you started with the system having no air in it. Assuming it was empty at some point, did you vacuum out the air in the system.
     
  28. jag-oo-r

    jag-oo-r Formula Junior

    May 27, 2015
    387
    #75 jag-oo-r, May 15, 2021
    Last edited: May 15, 2021
    Alright y'all..... I finally had a chance to spend some time on the car today. Turns out the A/C issue is relatively benign, as problems go. The electrical connector that attaches to the compressor clutch has a burned socket on the negative side. No sign of burning inside the female connector, (clutch side), so I presume this is residual from the past compressor/ clutch problems that the previous owner addressed (at beginning of this thread).

    I cleaned it a bit with a knife and then hit it with some dielectric grease. The compressor clutch immediately kicked on, but if I wiggle the connector, it kicks back off. So I'll plan to replace the connector.

    But there's the rub: anybody know where to buy such a connector? It's obviously going to be speciality, but surely it's available someplace?

    Help? ;-)

    Edit: amazingly, I think this is the correct one. It sure looks right.

    https://www.amazon.com/dp/B07CZ7FBVT/ref=cm_sw_r_cp_apa_glt_fabc_Z1G6XR1X6VQX2KYCTG55


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