My stupid radiator fan!

[albevan]

my radiator fan is randomly running and flattening my battery. have done a search but revealed nothing.

went out to my car at work yesterday lunchtime and couldn't start it. the batt was dead as a dodo. one of the lads came out to jumpstart it and when i popped the bonnet the smaller fan (the one on the drivers side of the car) was running.! obviously it was rotating slowly cause it had been running for 5 hours. Anyway i went to the shops and left it running to get a little charge in the batt. all the time the fan was running even though the engine was cold. got back to work and switched it off, fan still running. disconnected batt so i could have a poke around in the bay without fear of losing fingers, poked a few leccie plugs but could see nothing. one plug i did pay extra attention to was towards bottom of engine bay as you look down past the offending fan looks like it plugs into a water pipe but couldn't be sure. i reconnected battery so i could lock the doors, and lo and behold the fan DIDN'T come back on! result i thought i am an engineering god. when i left work car started straight up like nothing had ever happened, got it the 5 min drive home got out, and visually checked the fan was not running and went in for my tea, feeling all smug. vag commed it and it came out with nothing so i thought it was just a random event. come out today to go out and it's dead. obviously it waited for me to get in the house and started running again! i'm at a bit of a loss, has anyone heard of this or have any suitable remedies. not sure if the infamous temp sensor has anything to do with it but i replaced mine 4 months ago for one with a green top, so i don't think that is a factor. any help would be greatfuly appreciated, sorry if this is a bit waffly and rambling but it's my first thread so be gentle! cheers people!

 

[albevan]

please, anyone? am i looking at a fuse or relay, or could it be something more serious.

 

[Big_daddy]

faulty switch!
try linkin it to diagnostic and it should pick up the fault of dodgy sesnor/switch

 

[albevan]

i have tried that a couple of times but nothing is coming up. switched it off yesterday, and fan didn,t come on, i stood with it for 15 mins, and no fan. come out to it a few hours later and it's RUNNING again! it's as if it's purposly waiting for me to go in the house!

 

[barryg]

i have tried that a couple of times but nothing is coming up. switched it off yesterday, and fan didn,t come on, i stood with it for 15 mins, and no fan. come out to it a few hours later and it's RUNNING again! it's as if it's purposly waiting for me to go in the house!

Did you get this sorted ?? to me it sounds like a faulty fan control module (little black box under the battery I think)
As far as i know it wont show up on vag com as its not connected to ecu.

 

[albevan]

i think it was a sticking relay in the end, what i forgot to mention in my original post was that the car had sat unused for a month when it happened. any way i popped bonnet after a drive about a week after it started, to see if fan was running, it was, but then i heard the sound of a relay somewhere under the bonnet "having a fit". the relay went quiet and the fan stopped. that was nearly 3 months ago and it has not happened once since.