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HELP!! AC clutch relay!

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joe01952 View Drop Down
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  Quote joe01952 Quote  Post ReplyReply Direct Link To This Post Topic: HELP!! AC clutch relay!
    Posted: 09-Jun-2011 at 17:40
Does anyone know where and what number the %#^&#^!!
AC Clutch relay is?
My ac is charged but hot, wanted to check the relay first
If you knew how to jump it , that would be even better

Thanks
Joe
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yesimalex View Drop Down
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  Quote yesimalex Quote  Post ReplyReply Direct Link To This Post Posted: 10-Jun-2011 at 00:14
Originally posted by VWAffe

Points of order:

- There is no clutch on the W8's A/C compressor. It's internally (electronically) regulated, and always turns with the engine.

- The heater core does not have a bypass... so it's always "on".

Sounds like your car is having a Climatronic control issue. If the compressor is healthy (a good AC tech can tell a lot by watching pressures) and is being properly regulated (as in turned on - see above about pressures), you likely have an airflow issue - as in the air distribution flaps are not being positioned correctly by the Climatronic. That could be a problem with the Climatronic, wiring or the flap servo motors.




Check the post that SirRange made about using the search. Lots of topics about various A/C issues come up and everyone of them points to a clutchless design of the W8.

Custom Google search to help

PDF explaining how the compressor works page 13

After further reading (because I am having AC issues as well). It would seem that if you were getting any cool air at all the compressor is still functioning. Which is where I am it's cool air just not as cool as it used to be. It also said it would throw an error code of the freon or whatever is low. My question is this a CEL code or could it be whats making my climatronic flash almost every start.

Sorry for thread jacking but I answered your question for you so

Edited by yesimalex - 10-Jun-2011 at 00:32
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rustybronco View Drop Down
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  Quote rustybronco Quote  Post ReplyReply Direct Link To This Post Posted: 10-Jun-2011 at 02:19
Hmm... in April I just refilled my freon. I don't recall the exact numbers but it was low enough that it was not putting out cool air. I never saw a code scanning with vag-com and definitely did not get a CEL.

Have you guys checked your freon pressure?
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  Quote joe01952 Quote  Post ReplyReply Direct Link To This Post Posted: 10-Jun-2011 at 03:18
im at 25 psi at 65-60-F 27 at about 80F I know its on the low side but within range?

Just dont want to over fill , but maybe I should try some?
The Climatic control doesn't throw any errors nor the CEL

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  Quote joe01952 Quote  Post ReplyReply Direct Link To This Post Posted: 10-Jun-2011 at 16:35
PLEASE someone tell me I' stupid!!   

I just relized the pressure I gave u at 27 psi was with the car off(lowside) Im supposed to check with max air running, right?
Im probably way overcharged, wish I wasn't at work, now I'm jonesing!
God, u'd think it was the first time in this country!!! lol
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  Quote yesimalex Quote  Post ReplyReply Direct Link To This Post Posted: 11-Jun-2011 at 06:42
When the Climatronic panel blinks at startup, that means it's recognized and stored some sort of fault condition. The best and most definitive way to find out why is to check for fault codes using VAG-COM, or take it to the dealer, because the fault condition will be held in memory for quite some time and you won't have to try to replicate the problem on-the-spot. However, if the only problem is the AC compressor won't kick on, there is some diagnostic information available using just the control head itself that might give you a basic idea of why.

    * Key in the ignition, turn ignition to ON but do not start (it works anytime the ignition is on, but we want the car to be in a known state).
    * On the Climatronic control head, hold down the ECON and Colder buttons, then hit Fan Down. The display will change to a diagnostic view.
    * The Colder and Warmer buttons will move between display channels. There are 70-something channels, the channel you're on is displayed on the right. If you just press them a few times you'll see the channel number change and temperature and other numeric values displayed on the left.
    * Navigate to display channel 19. On a normally functioning vehicle in a key-on, engine-off condition, it should display "5". Here is a list of values, along with my comments in bold:

    Bentley Repair Manual list of A/C clutch -N25- switch-off conditions

    Code 0: -N25- is not switched off (normal operation)
    Code 1: -N25- switched off by A/C pressure switch -F129- due to excess refrigerant system pressure.
    Code 2: -N25- switched off because of fresh air blower -V2- with control module for fresh air blower -J126- malfunction.
    Code 3: -N25- switched off by A/C pressure switch -F129- due to insufficient refrigerant system pressure.
    Code 4: Not displayed.
    Code 5: -N25- switched off for 4 seconds (no malfunction). Code 5 is only displayed for 5 seconds. If continuous, check speed signal. (no engine speed signal is expected if the engine is not running)
    Code 6: -N25- switched off with ECON button (no malfunction).
    Code 7: -N25- switched off because A/C system is switched off via button for fresh air blower speed (no malfunction).
    Code 8: -N25- switched off because ambient temperature is below 3 ° C (37 ° F) (to prevent icing, no malfunction). Check temperature sensors -G17- and -G89-.
    Code 9: Not displayed.
    Code 10: -N25- switched off because voltage supply is below 9.5 V.
    Code 11: -N25- switched off by "excessive coolant temperature" warning lamp via Climatronic control module -J255-.
    Code 12: -N25- switched off by Automatic Transmission Control Module (TCM) or Engine Control Module (ECM) via Climatronic control module -J255-. (this is full load/accelerator pedal kickdown, or possibly engine idle speed too low)
    Code 13: -N25- switched off because voltage supply above 17 V.
    Code 14: Evaporator temperature, no function.
    Code 15: Wrong or no vehicle coding.
    Code 16: Malfunction source in control circuit.
    Code 17: Pressure sensor malfunction.

When you start the car, the channel 19 display should transition from 5 to 0 within a few seconds. If it doesn't, look up the number it does display from the list above. You'll have to wait for the no-A/C condition to appear again before you'll be able to use this method to find out what's going on, however, you can enter the diagnostic mode at any time the ignition is on. Next time you see the display flash at startup, switch to diagnostic mode and make note of the value in channel 19. When you are done using diagnostic mode, touch ECON to exit.

Quote:
Originally Posted by MikedW8 View Post
Also, the car always reads the outside temp ~ 10-12 degrees warmer than it really is. It doesn't matter if its winter, summer, etc. Although when I first turn on the car, the temp is pretty accurate. I'm thinking there is some engine warmth interference? Can the dealer fix this?
One of the two ambient temperature sensors may be giving high/bad readings. The first sensor is the -G17- Outside Air Temperature Sensor, which is located in front of the A/C evaporator. Assuming you have a front license plate, look straight through the lower grille an inch or two directly below the lower right-hand plate screw and you'll see it. The other sensor is the -G89- Fresh Air Intake Duct Temperature Sensor. It's a small white prong extending into the fresh air intake, a couple inches under the pollen filter. For reference pictures, I'm sure if you search, there's writeups on here somewhere for accessing and replacing the pollen filter. Actually replacing -G89- might be substantially more difficult, if it comes to that, the dashboard might have to come out.

To verify the readings you get from each temperature sensor, enter the Climatronic diagnostic mode as described above and look at these channels:

    Diagnostic channel 64: Temperature displayed on Climatronic control head, in Celsius. This is calculated by combining the -G17- and -G89- readings, and a correction factor if the vehicle has been parked to allow for heat soak. I think the correction factor is "standing time" in minutes, which can be viewed using one of the diagnostic channels but I don't have the channel number handy, and also in VAG-COM.
    Diagnostic channel 5: Actual, un-adjusted reading from -G17- Outside Air Temperature Sensor, in Celsius.
    Diagnostic channel 6: Actual, un-adjusted reading from -G89- Fresh Air Intake Duct Temperature Sensor, in Celsius.

Check both sensor readings in channels 5 and 6 and see which of the two are giving "hot" or no readings. If one of them is giving bad readings, check for physical damage or debris obstructing their correct operation. You state the problem is less present or not present at the moment of cold startup, so -G17- being obstructed or out-of-position would be a strong consideration due to its proximity to the hot A/C condenser and coolant radiator components. It should be held by a small arm about an inch in front of the A/C condenser coils, not in contact with anything.

Any Volkswagen dealer will be able to find and fix both of these issues, using methods very similar to the above. If you decide to carry out these checks yourself, please let us know how it goes.

*Credit to jyoung8607 on the passatworld forum for this juicy bit.

Just ran out to test it, mine goes from 5 on KOEO to 12 then to 0 but I was getting cold air. Will repeat when I get hot air out of ac unit.

After letting the car sit in the sun I get a code 17 KOEO that continued to code 17 after starting. Restarting the engine gets the 5 -12 -0 sequence.

The outside temp sensors both seem to be putting out reasonable temps 30-36 So it sounds like I have a bad AC pressure switch?

Edited by yesimalex - 11-Jun-2011 at 21:17
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