Crap A/C issue

When you did your pressure check both the fans should have been turned on. AC needs fan to work for AC to function

Fan hasn't worked at any time since testing. Thought that may be due to that switch originally.

GTI's said:

When you did your pressure check both the fans should have been turned on. AC needs fan to work for AC to function

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I am pretty sure that the fan do not work if the AC is not cooling/pressure not building. I don't remember that mine worked much when the AC was empty, however then turned on directly when charged.

With a compressor shutoff code of 0=ON the fans should be on and I would expect to see the fans moving at whatever speed the system calls for. If the pressure was < 2 bar the shutoff code would be 3 and because of that code the fans for AC would be off. I do not see a specific compressor shutoff code for fans not working, but you sure would see a DTC in the ECU for that issue.

As said before, the compressor always work at 5% capacity (in ECON mode) because it has no clutch, that this the minimum it can work. That's why VW recommends not driving more than 10 minutes with the system empty, even though the compressor keeps some oil inside it can overheat. So not sure if the compressor codes applies.

I am pretty sure that the fans only come ON when pressure is built, for instance in ECON mode they are off or at least work intermittently while compressor is code 0.

Yes I know that the compressor is always turning on the MKV and that its displacement is change by the RCV, and that percentage can be from 0-100 depending on what SSP you are looking at. The only time it would not be turning is if its seized up, and in that case you better hope the override pulley works to prevent damage to engine.


IN ECON mode the compressor is off, shutoff code is 6, OP shutoff code has been 0 the two times it was posted.

"Here is a list of typical Compressor Shut off codes:
- 0 = Compressor ON
- 1 = Compressor OFF: Refrigerant Pressure too high (> 32 bar)
- 2 = compressor OFF: Basic setting not performed
- 3 = Compressor OFF: Refrigerant Pressure too low (< 2.0 bar)
- 5 = Compressor OFF: Engine Start Detection
- 6 = Compressor OFF: ECON Mode active
- 7 = Compressor OFF: A/C System / FAN OFF
- 8 = Compressor OFF: Outside Temperature too low (< 3.0 °C)
- 10 = Compressor OFF: Vehicle System Voltage too low (< 10.1 V)
- 11 = Compressor OFF: Engine Temperature too high (> 118 °C)
- 12 = Compressor OFF: Shut-Off requested by Engine Control
- 13 = Compressor OFF: Vehicle System Voltage too high (> 17 V)
- 14 = Compressor OFF: Evaporator Temperature too low
- 16 = Compressor OFF: Compressor Activation faulty
- 17 = Compressor OFF: No or implausible Signal Pressure Sensor
- 18 = Compressor OFF: Vehicle Speed Shut-Off
- 19 = Compressor OFF: Shut-Off requested by Central Electronics Control (Load Management)"

Can confirm that shutoff code was 0. I just switched it to "Econ"(weirdest naming convention, puzzled me for a while) and verified it showed a value of 6 to show econ was on. Should be vacuuming and recharging with dye this weekend to check it out further. Will post results.

easy87 said:

Can confirm that shutoff code was 0. I just switched it to "Econ"(weirdest naming convention, puzzled me for a while) and verified it showed a value of 6 to show econ was on. Should be vacuuming and recharging with dye this weekend to check it out further. Will post results.

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When you had code 0 did you happen to see if fans turned on.

Fans have not been on at any point during testing

Edit: Might upgrade it to this!

You could use that or one of those side window swamp coolers

http://www.2040-cars.com/_content/cars/images/89/621689/006.jpg

lol, what in the actual hell is that thing? It looks more turbine-esque. Allow me to ask this one before I go all the way with the vacuuming and pressure gauges.

I know that ~525g should be put in. But assuming I put in ~525g of freon, at 60f, what should the pressures be? I called a local dealership to ask and his response was
Hi:60
Lo:30

Which sounds terribly incorrect. Do you guys know what a normal reading with compressor off vs compressor on would look like? I just want to be as informed as possible before I start, as not to trip up anywhere.

I have the resting pressures tables from VW, I will have a look tomorrow. Should probably be around 4-5 bars from memory (engine off/stabilised temperature). Engine running with AC on will of course be higher.

Do not go by pressure, go by weight, if you vacuum and put 525g +/- 25 it will be fine. VW do not have high/low pressure tables, only resting pressures.

easy87 said:

lol, what in the actual hell is that thing? It looks more turbine-esque. Allow me to ask this one before I go all the way with the vacuuming and pressure gauges.

I know that ~525g should be put in. But assuming I put in ~525g of freon, at 60f, what should the pressures be? I called a local dealership to ask and his response was
Hi:60
Lo:30

Which sounds terribly incorrect. Do you guys know what a normal reading with compressor off vs compressor on would look like? I just want to be as informed as possible before I start, as not to trip up anywhere.

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Early form of car AC https://en.wikipedia.org/wiki/Car_cooler

Static pressure R134A, kept in mind that static pressure in a fully charged system and one that's undercharged can be hard to tell depending how far off they are. Thats why you need to know the charge weight in the system. Check the label on the car and also compressor for proper weight seeing that they used more than one style compressor in the MK5.




And the 30/60psi from dealer is just bad.

Man, you guys are truly incredible with the info! Looks like its gonna be a fun time! When re-charging from cans, I assume you just take it off when you feel you are close and weigh it to verify how much has been put in?

Yes, but cans are more for a rough top up because you need to properly pull a near complete vacuum on the system for at least half an hour to get the humidity out. When doing so, some oil will get out of the system and you should measure and refill that amount also. If you go the cans route, make sure that they do not contain any sealant.