Author Topic: AC woes again - PLEASE HELP A SUICIDAL MAN :-(  (Read 379 times)

Offline ljc19630

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AC woes again - PLEASE HELP A SUICIDAL MAN :-(
« on: March 22, 2020, 11:23:13 AM »
Well the saga of the No AC continues. had a new AC condenser fitted when KO4 conversion done, Re Gas. Fitted new ambient temp sensor, AC pressure switch, RKX uprated solinoid valve - Still no cold AC. Took the car to local garage (ok guys) and they said that everything was doing what it should and the AC gas is full. Issue is that the fans are not coming on when AC is on LO which they should be!!! I read up on line and a common fault is that the compressor clutch that engages when AC is on has an issue with the splines rounding, hence it just spins. I took that off yesterday and the splines are fine. Checked bot 10a & 50a fuses and these are ok. Still no fans running. Spun up VCDS (again) as using the 08-HVAC diagnostic there was no faults showing, hence i used 01- Engine and initially got a P0691 fan 1 control circuit: short to gnd. That seems to point to the fan itself??? Doing my head in this and just want it sorted, but not clued up enough to determine if its the fan pack or compressor as everything else is new and been changed?? Been chatting with Pudding and his thoughts are the compressor, but only got the P0691 error yesterday  :thinking: :thinking: :thinking:- ANY HELP MUCH APPRECIATED :happy2:

Offline ljc19630

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Re: AC woes again - PLEASE HELP A SUICIDAL MAN :-(
« Reply #1 on: March 22, 2020, 03:51:45 PM »
Well we have another head f*ck with this now. After putting everything back together i went out foir a drive. No AC. Got home, fans not running. Left the car running for around 20 mins on my drive while i put away my hydraulic ramp. Pulled car on to garage drive, opened bonnet and f*ck me both fans running and we have Coooooooooooooold AC. Gonna do another VCDS test and see if any faults come up - WTF is going on, as last year not long after i bought the car and once the warm weather started i noticed that the Cold AC wouldnt commence untill after around 10m mins of driving, but had so much changed since then???


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Offline ljc19630

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Re: AC woes again - PLEASE HELP A SUICIDAL MAN :-(
« Reply #2 on: March 22, 2020, 03:55:18 PM »
Further head f*cks - turned off AC, Fans stop. Turn back on AC no Fans  - WTF Checked with VCDS using 01- Engine and 08- HVAC and no faults. I’m totally stumped now


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Offline amanda

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Re: AC woes again - PLEASE HELP A SUICIDAL MAN :-(
« Reply #3 on: March 22, 2020, 07:34:36 PM »
Ok I am going to suggest something basic.........are you 100% sure all fans are working properly? Fan relays are prone to intermittent failure

Offline ljc19630

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Re: AC woes again - PLEASE HELP A SUICIDAL MAN :-(
« Reply #4 on: March 22, 2020, 09:12:11 PM »
Not 100% sure. Like I said when AC is on LO, fans not working. Today was around 11 degrees so assuming ambient temperature was ok. But after leaving the car running for around 20-25 mins the fans kicked in and Cold AC prevailed. Why the fans are not kicking in from the get go when AC is on LO is the issue????


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Offline RedSwede

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Re: AC woes again - PLEASE HELP A SUICIDAL MAN :-(
« Reply #5 on: March 23, 2020, 09:48:28 AM »
I have no idea how the Mk5 AC system works, but, this absolutely sounds like corroded/carbonised/dirty contacts on a switch, now that you say it worked once. Plus, my guess is that this is not an overly complex system, so just try to break the problem down.

Is there a relay controlling the fans? Is there a switch on the compressor clutch that feeds back when it is in? I would check that kind of thing throughout the whole system.

Offline ljc19630

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Re: AC woes again - PLEASE HELP A SUICIDAL MAN :-(
« Reply #6 on: March 23, 2020, 09:56:18 AM »
Yeah its an odd one. I know for a fact that the fans should both spin up when the AC is on LO, but its almost like the engine needs to get to a certain hot temp before anything happens. The fact that the AC did work and blew cold, to me rules out a compressor fault and points towards a duff main fan, as this controls the small fan, but then again they BOTH worked, but now fcuk all again so far i have

had the clutch off the compressor and the splines are fine
replaced compressor solenoid for an RKX unit
replaced ambient temp sensor
replaced AC pressure switch
new condenser fitted and re gassed

Offline ljc19630

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Re: AC woes again - PLEASE HELP A SUICIDAL MAN :-(
« Reply #7 on: March 23, 2020, 12:18:33 PM »
Now investigating Fan Control Module 1J0919506M as read that this is also a big cause of issues and its the part that sends signals to the compressor and fans, hence could be fcuked!!!! Gonna whip out the battery & tray as believe its under there

Offline muff1991

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Offline ljc19630

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Re: AC woes again - PLEASE HELP A SUICIDAL MAN :-(
« Reply #9 on: March 23, 2020, 01:09:01 PM »
Thanks Shuan. So have taken out battery and tray and noticed exposed cable to the 200a SA fuse
Have re sealed this.
Can anyone confirm if the fan control module is an actual plug in box



OR is it part of the large fan motor itself as I can’t find anything after taking the battery box out????

P


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Offline ljc19630

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Re: AC woes again - PLEASE HELP A SUICIDAL MAN :-(
« Reply #10 on: March 24, 2020, 05:51:32 PM »
Update on this
Managed to get a “loan” fan pack to try from my sons mate who has a parts business. Fitted today and made no difference. Drove back to return the pack and car takes 10 mins of driving before ANY cold AC blows. You can feel the change, as I timed it. Then when engine is turned off and the on again, AC on LO, no fans run. Takes another 10 mins before AC blows cold. I’m now angling towards the compressor being at fault as have changed every else, and tried a new fan pack


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