Next time you use your A/C, pop the bonnet at the end of the journey before you shutdown the engine and check that both radiator fans are spinning smoothly. If either one fails it'll put extra stress on the A/C system. Rad fan failures are not uncommon, but can go undetected if the other is still functioning.

Here's a little thing linking various related info from various sources, including how to cheaply repair a failed low-speed internal resistor;

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

 

Can't remember if this handy thread  from the RossTech forums is linked in there so here's a direct link: http://forums.ross-tech.com/showthread.php?633-Tis%92-the-HVAC-Season

 

 

 

Edited 14 May, 20188 yr by Wino

15 hours ago, Wino said:

Next time you use your A/C, pop the bonnet at the end of the journey before you shutdown the engine and check that both radiator fans are spinning smoothly. If either one fails it'll put extra stress on the A/C system. Rad fan failures are not uncommon, but can go undetected if the other is still functioning.

Here's a little thing linking various related info from various sources, including how to cheaply repair a failed low-speed internal resistor;

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

 

Can't remember if this handy thread  from the RossTech forums is linked in there so here's a direct link: http://forums.ross-tech.com/showthread.php?633-Tis%92-the-HVAC-Season

 

 

 

Should they both operate then? i think only one of mine comes on and it makes a loud noise when it kicks in for a few seconds then cuts out. Revs drop a bit as it happens then rise back as the fan stops again

 

15 hours ago, Wino said:

Next time you use your A/C, pop the bonnet at the end of the journey before you shutdown the engine and check that both radiator fans are spinning smoothly. If either one fails it'll put extra stress on the A/C system. Rad fan failures are not uncommon, but can go undetected if the other is still functioning.

Here's a little thing linking various related info from various sources, including how to cheaply repair a failed low-speed internal resistor;

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

 

Can't remember if this handy thread  from the RossTech forums is linked in there so here's a direct link: http://forums.ross-tech.com/showthread.php?633-Tis%92-the-HVAC-Season

 

 

 

Top tip wino. Will check mine after journey home from work.

1 hour ago, JWvrs25 said:

Should they both operate then? i think only one of mine comes on and it makes a loud noise when it kicks in for a few seconds then cuts out. Revs drop a bit as it happens then rise back as the fan stops again

 

Sounds like low speed has failed on the main (?) rad fan, and the other one isn't working at all.

 

Check the blade fuses on the battery (under a cover next to strip fuses). There's a 30A one that does both fans at low speed.

Edited 15 May, 20188 yr by Wino

3 minutes ago, Wino said:

Sounds like low speed has failed on the main (?) rad fan, and the other one isn't working at all.

Yes the little one on the left (front on) doesnt work at all, the big one only works on fast. Guess ill have to do some investigation

See above edit about fuses. 

shame the link on ukmkivs doesnt have the photos anymore

Ive checked fuses and removed the smaller fan. it all turns over ok and brushes look fine etc but still not working.

 

Is it a two-wire single speed one, or three-wire dual speed?

its got 3 wires going into it

Check resistance between the connection that the brown earth wire goes to, and each of the other connections.