MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: ljc19630 on November 13, 2019, 03:29:05 pm

Title: Air Con Fans not kicking in from start
Post by: ljc19630 on November 13, 2019, 03:29:05 pm

Hi Guys,
Been having some issues (which seem commonplace) with my A/C. Initially, the A/C wouldn't kick in for around 8-10 mins from starting the car from cold. I did some research and also checked VCDS. This said that there was an intermittent fault with the V113 Recirc Flap motor. Pulled out the glove box and checked the motor and yep, it was sticking, so have changed this and thats now sorted. I have also changed the Compressor Solinoid Valve to an RKX part, as reading lots of good reports on these. AC seems fine now, However, today I started the car up from cold, Turned on AC, opened the bonnet and the fans were not running. Left the car for at least 30 mins running and still not kicked in? C I have also purchased an A/C pressure switch which i'll fit tomorrow, albeit VCDS isn't advising any issues? can anyone assist me with what this issue could be, or how I can diagnose using VCDS?

Cheers
Louie

Title: Re: Air Con Fans not kicking in from start
Post by: FJB on November 13, 2019, 04:04:51 pm

AC wont run if the outside temperature is 3 degrees or below.

Title: Re: Air Con Fans not kicking in from start
Post by: ljc19630 on November 13, 2019, 04:07:08 pm

Quote from: FJB on November 13, 2019, 04:04:51 pm

AC wont run if the outside temperature is 3 degrees or below.

It was definitely higher than 3 degrees. This morning at around 10am was around 7 degrees - Could the Ambient Air Temp Sensor be faulty and if so would VCDS show this up?

Title: Re: Air Con Fans not kicking in from start
Post by: FJB on November 13, 2019, 04:22:10 pm

with a scan tool with engine running and ac on go to air conditioning / live data / group 001, this should give you a compressor status code, whether its on or off or too cold. If it says on with pressure ok it is likely to be the compressor or control valve. You wont get a fault code for broken compressor or valve, only for low pressure.

Title: Re: Air Con Fans not kicking in from start
Post by: ljc19630 on November 13, 2019, 06:08:08 pm

Thanks buddy. I’ll have a play in the morning as off on leave all week


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Title: Re: Air Con Fans not kicking in from start
Post by: ljc19630 on November 14, 2019, 11:20:13 am

Have tried as you explained. Not sure if I’m in the correct setting but pic below is what’s showing??

(https://uploads.tapatalk-cdn.com/20191114/93ee44ce2d28a3cd151fd7f79ed19efd.jpg)


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Title: Re: Air Con Fans not kicking in from start
Post by: FJB on November 14, 2019, 11:52:31 am

Here are the codes:

0 - Compressor on
2 - Off, Blower Fault
3 - Off, Pressure Low
5 - Off, Engine Start Not Detected
6 - Off, Control Panel Switch Econ Mode
7 - Off, Control Panel Switched Off
8 - Off, Outside Temperature Below 3 Degrees
10 - Compressor Supply Voltage Low
11 - Coolant Temperature High
12 - Turned Off by ECM
13 - Off, Compressor Voltage High
14 - Evaporator Temperature Too Low
15 - Coding incorrect
16 - Activating Signal Fault
17 - Faulty Pressure Sensor Signal

Title: Re: Air Con Fans not kicking in from start
Post by: ljc19630 on November 14, 2019, 11:56:59 am

(https://uploads.tapatalk-cdn.com/20191114/0f435300f69f4a549066d4f0b3ea2222.jpg)

Got them and also showing the measuring blocks for group 1,2,3 below. Looking ok????



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Title: Re: Air Con Fans not kicking in from start
Post by: FJB on November 14, 2019, 12:05:05 pm

It looks like your compressor is turned on. When you turn it on and off does the engine load change?

Title: Re: Air Con Fans not kicking in from start
Post by: ljc19630 on November 14, 2019, 12:07:35 pm

Yep - revs drop when off and rise when on. Fans are now running as just did a full self test. Is there a way to test just the fans?Confused.com



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Title: Re: Air Con Fans not kicking in from start
Post by: FJB on November 14, 2019, 12:18:51 pm

I think you may have a problem with the control valve, the gauze on the control valve get blocked with debris, very common if your entire system is not flushed and condenser replaced after a compressor failure. It is easy to clean and bench test the control valve, but you will need get the refrigerant recovered and re gassed afterwards to check it.

Title: Re: Air Con Fans not kicking in from start
Post by: ljc19630 on November 14, 2019, 12:22:59 pm

Where and what is that control valve? I’ve already changed the compressor solinoid, and have purchased a new ac pressure switch and ambient temp sensor. They were cheap enough so will fit these anyway, but intrigued as to the sensor your referring too? I’ve had a new condenser rad fitted when R-Tech did my ko4 conversion, and also re gassed. I’m up there on Saturday so will ask them to check out, but let me know what sensor you on about too

Oh and thanks for all ya help bud


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Title: Re: Air Con Fans not kicking in from start
Post by: FJB on November 14, 2019, 12:33:10 pm

The control valve is the solenoid you replaced, it has a gauze filter on it, and if there has been a previous compressor failure then it can get clogged.

Title: Re: Air Con Fans not kicking in from start
Post by: ljc19630 on November 14, 2019, 12:36:31 pm

Ah I see. Well AFAIK it’s the original compressor on the car, so if that’s the case wold this still be relevant? I fitted an RKX solenoid as heard good reports on these from various peeps that have fitted.


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Title: Re: Air Con Fans not kicking in from start
Post by: FJB on November 14, 2019, 12:47:28 pm

It may not be the problem, and if its recent and is good quality is unlikely to have failed. If all else fails test it on the bench to make sure.   

Title: Re: Air Con Fans not kicking in from start
Post by: pudding on November 15, 2019, 10:04:29 am

My fans don't come on after start-up either, even on LO, but my A/C is fully functional.

The fans are PWM speed and temperature controlled from both the engine and A/C controllers.  I think you will find at this time of year, the fans won't just come on arbitrarily, but rather there is some ambient temp intelligence going on.   The A/C has less work to do over winter to achieve the cooling targets.

Title: Re: Air Con Fans not kicking in from start
Post by: ljc19630 on November 15, 2019, 10:30:48 am

Thanks, Kev, all a learning curve this! I'll test it out on my way up to R-Tech tomorrow morning. Thing is the other week I went to Maccydees and sat in car scoffing my grub :party:. Had engine running, AC on and it was pissing down and very damp outside. Windows started steaming up?? Turned fans up to the max, but it took at least 15 mins to clear. This was before I changed the AC Solenoid to an RKX part, and had it re-gassed. I also changed the Recirc flap motor as VCDS was showing as an intermittent fault. I'll leave the car out of garage tonight as early start and also will then be at ambient temperature, so if AC is working as it should I won't get any steaming up, as prior it was around 10 mins from a cold start for the ac to start performing as it should.

Title: Re: Air Con Fans not kicking in from start
Post by: pudding on November 15, 2019, 10:48:00 am

It certainly is! The fans on VWs have been a pain in the hoop since the VR6.  It's really difficult to find on the web exactly what conditions trigger them, but over time you figure it out from observations! 

You may have fixed the demisting issues with your new parts and regas.  Yeah the demisting should be pretty quick when everything is working properly, certainly not as slow as 10-15 mins!