Erratic Cooling Fan

[MOTOW]

Hi,People
When my 1999 1.8 SPORT A3 is running the fan keeps switching on and off even when cold.
Any ideas.

[RickT]

Themostat of the fan may have gone... causing it to short to go on and off..

Im not sure if it would be reported in VAG-COM...

RicKT

[MOTOW]

Thanks, I will run a diagnostic on it tonight and check thermostat and sensor at weekend.

[RickT]

let us know know you get on

RickT

[MOTOW]

I have not had a chance to do anything yet .
Will let you know what I find.

[MOTOW]

Hello Rick, nothing showed up on diagnostic.
I am now going for thermostat as you suggested plus wiring and sensors.
I will have to wait as fault is intermitent.

[Nexus]

It will most likely be a faulty 1st speed series resistor in the fan units itself, this is mostly highlited when the A/C is switched on and 1st speed is automatically turned on to cool the condensor and draw air through it but if the 1st speed does not run the system overheats and kicks the 2nd speed in harshly, in turn it cools down and goes off but the cycle is repeated. check the 1st speed built into the fan units for failure. (can be checked with a test light on the thick main red cable going to the fan unit, 1 is 1st speed the other red is 2nd speed. with a/C on (if fitted) there should be continuous 12v at the 1st speed suply wire. New fan units will be needed if the fault is with the 1st speed resistor as they come built into the fan.

[MOTOW]

Thanks will look into this when I get a chance.