A/C Woes | FerrariChat

A/C Woes

Discussion in '365 GT4 2+2/400/412' started by SouthJersey400i, Aug 9, 2020.

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  1. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    For the first 10 years I have owned my 400i, the A/C was ice cold and I often had the evaporator freeze ups that have been well documented in this forum. My solution to the freeze ups was to put a manual switch to cur the compressor off for a few minutes with cooling fans still on. This worked well for a couple of years.

    Now I have the opposite problem, no or very little cooling. This has gone on for about 2 years, once I thought I had it licked when I found the one front fan in front of the condenser had quite working but still no help when resolved.

    Yesterday I rechecked the pressures on the compressor and they are basically all within spec.
    Starting ambient temp about 80 F (27 C)
    Static comp press 2.8 bar in 2.9 bar out
    Idle comp press 1.8 bar in 7.0 bar out
    2000+ RPM
     
  2. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    Sorry I hit something and posted early. I'll continue:
    Starting ambient temp about 80 F (27 C)
    Static comp press 2.8 bar in 2.9 bar out
    Idle comp press 1.8 bar in 7.0 bar out
    2000+ RPM 0.6 bar in 9.0 bar out
    Cooling front vent -2 F; Rear -3-4 F
    Ran steady 2500 RPM for several minutes and garage heated to 90+ F (32 C)
    Idle (lower) comp press 3.2 in 8.0 out
    1500-3000 RPM comp press 0.8 in 10.5-11 out
    Cooling negligible

    My conclusion is that with R12 Freon the pressures are pretty close to being in spec, so the amount of Freon is about right and the compressor is functioning pretty well. What the hell is wrong with the evaporators?? Ny ideas? Neither front or rear are cooling, maybe the rear a little bit and the rear has alwayscooled better than the front. Rear evaporator is also more easily accessible if I knew what to do.

    One common item that I am concerned about is the control module that sits on firewall behind the battery that somehow controls the distribution of liquid Freon to the two evaporators.

    Any ideas? All ideas welcome.

    My plan if the fix involves evacuating and pulling vacuum will be to switch to propane and be done with R12. However, I have no confidence that just making that switch will solve my problem.
    Ken
     
  3. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    If the evaporator is freesing the culprit is the snowflake button, as it is the one supposed to shut of the compressor. There is a second safety: the valve at the entrance of the evaporator. This valve has a sensor on the evaporator output and once the freon is freesing, this sensor is expected to shut off the valve (this is a mechanical device) which increase the pressure on the drier which in turns shuts off the compressor (there is a pressure switch in the dryer). So freezing evaporator means that both (snowflake button & evaporator valve) safety systems are not working properly...

    On the dual AC system, this is slightly different as the snowflake buttons are not supposed to switch the compressor, instead they operate the two electric valves located near the battery. So they shut down their own circuit. I presume that when both circuits are shut down the compressor is also shut down but you would have to check the diagram.

    My guess is that you have a faulty mechanical valve, (the one on the evaporator that freezes), so liquid freon had an opportunity to build up in the system. From then on no definitive answer on the component that was damaged by the liquid freon. The compressor usually do not like it, but hopefully the tubing passes quite close to the exhaust, so the freon has an opportunity to reheat before it reaches the compressor. A seized/destroyed compressor is easy to spot. As there is no obvious horror story you are left with the electric valves of the control module (?). Have you checked their relays?

    If I were in your shoes I would replace the relays, the 4 valves (2 evaporator valves + 2 electric valves of the distributor module) and the dryer (in order to have a working pressure switch).
     
  4. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    Raemin
    Thanks for some leads.
    My evaporator is clearly not freezing; it hardly cools at all. Yes, it used to freeze a few years ago and cooling was great. I resolved that and have had good cooling until two years ago. The compressor is not shutting down due to high pressure; it keeps running. As my data shows, compressor does not reach the high pressure setting. I replaced the dryer some years ago and it has the combined hi / lo switch contact. System has never been evacuated or at low pressure since replacing the dryer and the glass is clear.

    You have given me two leads. Since it is a whole lot easier to work on the rear evaporator I will remove the trunk panel to see what I can see when running A/C. Some years ago I re-taped the bulb with that sticky insulating tape. Is there anyway to manipulate the evaporator valve manually??

    Second, I will check the wiring diagram to see how the module behind the battery operates and check / change the relays. If I feel comfortable with the wiring I may try activating the module manually with a test wire.

    Anyone else had the issue that I am having or any other ideas?
    Ken
     
  5. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    New driers do not have a glass as you cannot spot colour change with the newer blend of gas. So this is obviously from old stock.

    You could activate the evaporator valve manualy: just keep the sensing probe away from the evaporator exit tube. As long as the probe is not seeing a freeze it let's the valve open.

    For the front evaporator valve,
    you can access it if you remove the passenger seat, the glove box and right side trim of the center console. No need to remove the whole dashboard.
     
  6. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    À faulty drier will let escape some silica that can easily stuck the evaporator valves.

    The condenser is the old fashioned type, so no super thin parallel flow tubing that are easily taped by debris. At least this should be OK...
     
  7. christc

    christc Formula Junior

    Mar 3, 2013
    444
    Germany
  8. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    Changing the valve is a 2hr job, as you do not have to remove the whole dashboard. As the car seems to have a 10+ year old dryer and given the previous freezing issues, I would just rush to NAPA and spend $15x2 on new valves.

    No idea on the cross reference for the two electric valve of the distribution module but this should also be generic.
     
  9. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    Chris, great link. Crazy to hear so many issues with clogged valves especially with Ferrari's. This tells me this issue is very likely my problem.

    Raemin, I wish these jobs were still that easy for me but my flexibility has diminished with lots of titanium installed in my spine over the last three years. My plan is to attack the rear evaporator and see if I can get it to work. First I will try to do it electrically but if that does not work I will go for the valve replacement, which means I will need to buy a vacuum pump and the propane refrigerant I plan to use. That would be a good time to replace the evaporator many US cars have one that is nominally the same size; I think when mine was last changed it was sourced in US (I have part # to compare).

    If I can get the rear working I will be very happy until I take car off the road again at end of November for its winter R&R. My wife and I have been very comfortable on many trips only using the rear AC. The front evaporator will then be on my winter list when I won't mine the "2 hour" job to get to that evaporator. Once I have vacuum pump and the propane refrigerant, I won't mine doing double work.

    I hope to know more this weekend.
    Ken
     
  10. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    Raemin et al
    I got side tracked by eye surgery and just getting back to my A/C. I spent a lot of time reading the manual and tracing the wiring diagram. Depending where you read some items have different names that sound similar to other items. Then there is the issue that Fig 7 and 8 on page I10 of the manual are labelled backwards. Figure 6 on page I9 is also confusing as the arrow is pointing to the compressor not the evaporator coil.
    I finally have some understanding of the system. For the dual A/C system the two snowflake knobs along with a simple bulb (no coil) control "antifrost valves" located behind the battery in one valve body. These valves fail OPEN, energize to close. So one way to force them open (at least electrically is to disconnect the wire; at least this is a way to test electrical functioning although manual says you can hear them click with the motor not running.
    Today I removed the insulation material for the rear evaporator controls and I confirmed my understanding of how this works. Tomorrow I will follow the manual controls checks but I believe that is all working unless the anti-frost valves are not opening. I took two pics with insulation off.
    I did find the coil for the Expansion Valve was on top of rather than under the outlet pipe. How significant is that? I moved it before taking pics.

    Raemin, you said run to NAPA and buy two (expansion) valves. Do you have a part number? Will fittings and operation be compatible?

    More to follow.
    Ken


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  11. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    I do not have any-more the Napa ref (they do not ship to my country at a reasonable cost so did not keep record of their references). Here his the summit racing (four seasons) reference : FSS-38683. That's for the front valve (I assume rear is the same one). It is a perfect match to the original one.

    Do not forget to place the sensing bulb on top of the tubes and not on the bottom. The oil that flows in the system is somehow isolating the bulb from the cooling fluid, so your valve may not close the system soon enough.

    FSS-35845 is for the thermo cycle switch (a.k.a snowflake switch). You can find on Aliexpress some electronic alternatives. These could be easier to install on the rear aircondtioning condenser. Be it mechanical of electronic, this switch is cheap so worth changing given your prior issues.

    Add to this the Nylog thread sealant (blue or red depending on your gas) and Cork Tape.

    Hope this helps
     
  12. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
  13. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    Sensing bulb positioning explained :
    http://forums.pelicanparts.com/porsche-911-technical-forum/759863-ac-expansion-valve-tape.html#post7539248

    Carl Rose detailed 328 AC instructions. This was the most helpful source of informations for my AC rebuild. Please note that the 400i dryer does not have the same constraints as the 328 (the regular FSS-33255 works well for me), all the rest is applicable to our cars.
    http://www.ferrari.cdyn.com/carl_rose_docs/

    I am also enclosing the York Service Manual just in case...
     

    Attached Files:

  14. Tojo

    Tojo Formula Junior

    Apr 12, 2002
    481
    Sydney
    Full Name:
    Tim
    FYI you can punch those part numbers into Rockauto.com too and get the same products. Prices are similar within a few dollars but Rock Auto's shipping rates for customers outside the USA was quite a lot cheaper than Summit for me

    Sent from my SM-G935F using FerrariChat.com mobile app
     
  15. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
  16. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    I have finally done all the electrical checks. Results, some B&W and others not so clear: (all tests done with fully charged battery, motor not running):
    - Rear expansion valve coil was on top of outlet pipe as it should be. Did not pull glove box to check front.
    - Front and Rear fan switches and relays all working okay.
    - Compressor Clutch and Oil Pressure switch and relays (simulates motor running) work okay
    - Front and Rear T-Stat switches operate respective relays (snowflake switch)
    * After stroking rear switch many times the on/off point kept rotating (not the switch body) but contacts still open and close
    - Anti-frost valves (behind battery) did not initially seem to function. I had to disconnect the condenser fan to try to hear them. Front valve gave a very wimpy click. Rear valve did not seem to click at all. This was done by turning T-Stat switches on and off. Battery was out and I was using jumper cables to power car. I used test wires to test valve action with power direct from battery. On first-second try they each gave the same wimpy click but after stroking a few times they gave a nice "snap" like a solenoid valve should. I went back to switching valves using the T-Stat. Front one was back to its wimpy click and I could not hear or feel the rear one. Maybe there is enough voltage loss thru circuits with motor not running to not give enough volts to snap the switches??
    - I bench tested the relay for the rear Anti-frost valve (purple relay) and it stroked and opened and closed contacts as it should. However, I could not detect power on output wire to Anti-frost valve. I did not (yet) test the power wire to the relay which comes from the common relay next to the two individual relays. So this is one issue to work on. Of the newer plastic top relays should this relay be the purple or brown one? This is relay "W" or #113. It was during all of this on/off testing that the T-Stat valve off point started moving.

    My symptom of both front and rear cooling being minimal but not zero indicate clogged expansion valves and dryer debris would explain why both seemed to stop working in the same time period. So my plan is to do a major repair/upgrade over the winter. I will accumulate parts now. I will switch to DuraCool hydrocarbon refrigerant and replace the following parts: Front and Rear Expansion Valves, Dryer, Rear T-Stat valve Using the 328 forum post I will get an o-ring kit and sealant. I will hold off on using the cleaning solvent until I vent and remove the first expansion valve and see what I have.

    I will likely have part questions and suppliers in next month or two but I plan no work on the car until late October. I have two rallies to do over the next four weeks and hope there is no hot weather. Total miles will be at least 2500 in 4 weeks.
    Ken
     
  17. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    For the relays you are in the market for the ones that used to be brown but are now black... See https://www.ferrarichat.com/forum/threads/bosch-relays.112475/#post-142347640 and https://www.12voltplanet.co.uk/relay-guide.html. Here is a summary of it:

    • 0 332 204 101 is now 0 332 209 151 (purple). That's a regular B-Type (european) toggle relay, with 85, 86, 30, 87, and 87a terminals.
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    • 0 332 014 113 is now 0 332 019 151 (brown or black). That's a double output relay: a single input (#30) connects to two #87 outputs. There is no normally closed output (i.e no 87a).
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    • 0 332 014 140 is now 0 332 019 151 (same as above)
    • 0 332 015 006 -> still the same reference but blue case. That's a dual contact relay It has 85 and 86, 30, 87, and 87b terminals. Unlike "113", 87 and 87b are not connected together when the relay is open (only when the relay is closed).
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    A few notes :

    Be carrefull not to mix 209-151 and 019-151 !

    0 332 014 113 was the all metal cased we are used to, the first batches of 0 332 019 151were brown, whereas the latest i've received are now black.

    Unlike 106, non-bosch alternatives are easy to source. Maybe you should consider relays with some sort of noise suppressor (on the above illustration, there is a resistor across the coil, which the bosch do not have).

    The bosch relays are really strong, but they draw a lot of current, (200ma for the coil), so you'd better have a good battery when 16 of these are operating together with the fuel pumps and the aircon valves.

    Back EMF from the valve can be significant, maybe you should consider a diode in order to protect the relay contacts?
     
  18. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    Great info as always. It sounds like I have the correct purple rally for the Anti-Frost valve relays. This gives me a good way to test relays in the future without just guessing which contact is which.

    If you have followed my posts over last 13 years you will know that I have moved a lot of amps away from the panel in the passenger footwell. More recently I upgraded one of my alternators to 85 Amps so the relay amps should not be an issue. Voltage loss in those tiny little clips in the white connectors in the fuse/relay panel is another issue which could be affecting those anti-frost valves. Maybe that is what you are getting at with the diodes.
    Ken
     
  19. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    I have spent the last couple of weeks accumulating parts. Summit Racing's web site is so user friendly I ordered the two evaporator valves, one T-stat switch and the drier. I had some questions and they were quickly answered. The drier was ordered based on the Four Season's part #208625. Unfortunately the drier I received had male fittings on inlet and outlet. Our driers have a female fitting on the outlet. I did not want to add a coupling so I kept searching. I made several contacts and all those people had the two male fittings.

    Finally via a search for a Ferrari 328 drier I found the right drier on PolarBear.com (in Florida where Polar Bears are common). I got it today and it is correct. It is Polar Bears Part RD 129101. The actual part has only a small stock number sticker on the bottom, so I do not know their source but happy to have one with the right fittings.

    I'll start work in a few days.
    Ken
     
  20. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    Before removing the rear evaporator valve, I started work around the top of compressor. About 10 years ago a shop replaced the compressor and he got the routing of the hoses upside down with discharge on top of suction. This blocked the clear path for my cold air inlet to the RH air filter. I reversed the lines and there is now a clear path for the cold air inlet.

    In making this switch I found that the o-ring on the compressor discharge hose fitting appears to have a square cross section. I have a kit with all round section o-rings. I'm not sure if the old o-ring was compressed to square over time or is it supposed to be square. Does anyone know? See pic with black o-ring being the old one.

    I'm also posting two pics of the drier I got from Polar Bear. It has correct inlet/outlet fittings. Brass plug is where the pressure switch will go. It even has the old-school top glass window. The drier has a small label on bottom "HZ1601", not sure if that means anything.
    Ken
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  21. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    Do you mean the o-rings on the rotalock fittings? If so these are normally teflon (white) rings. Some new ones were supplied together with my compressor rebuild kit. I had to locally source these as it appears that once torqued they cannot be used anymore (so every time you remove the fittings, these have to be replaced). Here is the French listing so as to give you an idea of what they look like:

    https://www.ecoclim.net/compresseur/pieces-detachees-compresseurs/joint/york/p202A10/detail.php
     
  22. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    Raemin
    The pictures I posted were for the hose fitting into the top of the compressor that slide on the fitting. Do you thing the green o-rings will work there?

    You now have me worried about those Teflon gaskets. I removed the one fitting on discharge of compressor so I saw the flat Teflon gasket. Besides getting the hose orientation correct I needed to rotate that top fitting to be able to get my gage fittings on easily. I planned to use some Nylog sealant on them. I know they had been previously rotated and were not leaking. I will now look for a US source of the Teflon gaskets. Thanks for giving me one more thing to do!
    Ken
     
  23. raemin

    raemin Formula 3

    Jan 16, 2007
    1,825
    Lyon (FR)
    Full Name:
    R. Emin
    These do seem the correct ones. I cannot comment any-more on the size as I've put the compressor back in the car 2 weeks ago. The size does not seem overly precise: once these are "crushed" in the rotalock fittings they "spread" outside the groove and the square shapes ends up as a 4mm wide T shape.

    As said these are not regular (green) o-rings that are compressed, these are "crushed" (no better way to describe it).
     
  24. SouthJersey400i

    SouthJersey400i Formula 3

    Mar 14, 2007
    1,591
    Romulus, NY (Finger Lakes)
    Full Name:
    Ken Battle
    I checked my old compressor and those washers are compressed down inside the grove rather than T shape as you described. My compressor in the car they seem to have the T-shapre as I only see Teflon and not the metal that makes the groove. I will order a set and see how they fit. Thanks for your help.
    Ken
     

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