Fan problem.

[benjie]

B6 A4 1.9 TDI

Right, I have 2 fans at the front of the car. As I got home tonight, I tuned the air con off about 30sec before turning the engine off. Shortly after, I heard a fan in the engine bay winding down. Though it was unusual. Opened the door and turned on the ignition (not engine) and the fan came on for about 10 sec (the fan on the driver's side), then went off for 10 sec, then came on for 30 sec, then off for 5, back on for... I turned the ignition off after that. I assume it would just carry on like that.

I've had a bit of a search and come up with the control module for the fan, but I'm not sure my symptoms fit the bill.
I have a capacity prob with my air con if that is relevant - can't put speed higher than 4 or it just blows ambient air.

Any ideas guys?

EDIT: Just left the car for an hour and tried the ignition again & now the fan on the right is on permanently.

 

[dale86]

I had similar problem and it was due to car overheating but it wasnt showing on the temp guage as been over 90 must of been because the fan was doing its job anyway it was down to waterpump failure luckily caught it in time. This probably isnt whats wrong with yours but its worth a check as the waterpumps are prone to failure.

 

[benjie]

Thanks dale, further development...
Just driven to work, fan on all the time and today the temp gauge in the dash in't registering... I'm not starting to think it's the coolant temperature sensor... which was replaced a month ago!... because the symptoms now match what happened last time that went. though I'll keep what you said in mind...

 

[A3HAZ]

I have a similar sort of problem my fan comes on very randomly but doesn't stay on when ignition is off which sways me away from the module fault, anybody have any ideas on what it could be?