Hi all hopefully this gets posted in the correct section as I'm new to the forum so hello from me ... I was donated a 2004 fabia from my dad when my van died and I've never had the AC work and from information I gained from this forum I found the usual broken wires and fixed those ect. I also regassed the system myself about a week ago and although I'm not convinced it hasn't got a leak the AC did work however I think there may still be a fault so I will say what's happening.    Basically at idle with bonnet open and AC selected it takes what seems to be 30-40 seconds for radiator fan to kick in which runs for about 5 seconds and cuts out , it then after 30 odd seconds repeats the process 😳,  the engine is up to temp as been out on a drive . The AC definitely works better whilst out driving but what could be making the fan cut in and out ? Any help appreciated many thanks Carl 

Just to add it doesn't have climate control and its has a single radiator fan and it's the 1.4 tdi thanks 

The fan is twin speed, and the low speed function has failed. Common fault.

Can be repairable with a large external resistor wired in, or more straightforwardly by fitting a new fan.

 

https://www.briskoda.net/forums/topic/404143-radiator-fan-repair-courtesy-of-vortex-here-and-uk-mkiv-forum/

 

Thanks Breezy Pete il look into the low speed fan possibility  😀

Hi pete I managed to get around to checking the single fan by bridging the pins and found that when I bridge low speed pins nothing happens but I do hear a relay clicking,  the high speed kicks in when I bridge those pins , so does this mean my low speed resistor is fried as you previously mentioned? Many thanks Carl 

Yep.

Brilliant Pete my dad is very useful when it comes to soldering ect and has all the gear so he is going to do the external resistor mod by using your post as reference,  as with his confidence in soldering and how relatively cheap the resistor is its a no brainer,  is it just a case of undoing the 3 screws on the tripod thingy to remove the fan ? 

Yes, but watch out for rustiness in the heads, potentially causing non-full-depth bit insertion and head damage/rounding. Tx30 I think.

On first glance the 3 torx screws seem free of rust , I will go and try to free them up in the morning  so I know in advance of any issues 

All done Pete , wouldn't have been possible without your very informative post , we ended up putting 2 small bolts through the fan arm to keep the resistor fixed in place . . . Low speed now works but doesn't run constantly with AC on , It was running when I opened the bonnet after I got home from the 30 minute journey from my dad's,  not sure what's normal but the low speed is definitely working now 😀 

Well done.

Whether it runs constantly or not depends on whether the refrigerant pressure dips under the switch-off threshold (6.8bar from memory) when fan is running 

This in turn depends on ambient and demanded temperature,  and of course how much air is being pushed through the condenser due to vehicle motion alone.

 

Keep an eye on the plastic that resistor is leaning on, I suspect that resistor is going to get very hot in summertime, should that ever actually arrive.

 

The temperature down my way was around 15 degrees today and the first time I tested it after refitting the engine was cold , I will keep an eye on the plastic that the resistor is mounted too and if I get any issues il slacken off the bolts and put a strip of aluminium in there , thanks again for your help  😊 

It'll  be fine. Just looked up the melting point of ABS plastic and it's pretty high, 200+ °C. Not sure if it is ABS, but it may well be.

Should be OK unless the car catches on fire then 😆