Weird Fans cutting in at any time on GT TDI MK5

[frampsgti]

Hi

Well after getting my Mk4 GTI through its MOT this week its now the time for my MK5 GT TDI to go on some kind of protest!! this morning I woke to the sound of the fans on the golf cutting in and then switching off, they only come on for a few seconds before going off. The car had sat on the drive all night and had not been driven. Anyway got in it this morning and the battery was dead so through out the night the Fans have been coming on and off. I have two possible theories which Im hoping someone out there might be able to help with!!

The first one is that night it absolutly chucked it down all night so Im thinking that the ECU has got wet and is playing up turning the fans on and off!!

The second is that the fan control unit has decieded that now is the time to die??

At the moment the fans are disconnected and this has obviously stopped them coming on and off, has anyone had this problem or can anyone shed any light on it. Its a Mk5 Golf GT TDI with 2.0 engine, ive recently had the Temp sender unit replaced.

regards
Framps

[MaXXeH]

fans are not controlled by the ecu,  I would say your fan controller is playing up.

[simonpolly]

I had this on my old touran which is basically a mk5 golf,it was down to water getting into the electrics,they replaced the covers for the relays/fuses in the engine bay and a cover for the fan control unit.Why did`nt your alarm go off if the battery had gone flat?,mine woke us up as the battery was going flat due to the fan coming on and off all night long.

[frampsgti]

The alarm didn't sound coz it's switched off! But did go off!!! Today while driving it, it decided to die on me completely but I think that's because I drove it around forgetting to plug the fans back in!!! I'm certain water is getting in some how as it only happens when it chucks it down!!! Did changing the covers help???

[simonpolly]

The alarm didn't sound coz it's switched off! But did go off!!! Today while driving it, it decided to die on me completely but I think that's because I drove it around forgetting to plug the fans back in!!! I'm certain water is getting in some how as it only happens when it chucks it down!!! Did changing the covers help???

Yes it never happened again