Fan pulsing on off on off

[felix_kentish]

Hi, I'm new to Audi's (Just coming from a Nissan 200sx) and new to this forum. I've been looking over a lot of threads to get an idea of common problems fixes etc.
I have just bought an A3 1.8T Quattro and there are a couple of niggly problems. I have had a good search of these forums as well as google but no conclusive answer.
The fans on the car constantly pulse on/off/on/off regardless of temperature and alot of the time leads to the car running quite cold. I am awaiting delivery of VAG-COM and hope that will help but I was hoping some people had some ideas so i can check them before i plug in the laptop. Each time the fan comes on it is accompanied by a drain on the electrical systems and headlights dim etc.
Any ideas?

Cheers

 

[felix_kentish]

Could it be the fan control module? This seems like quite a common problem but usually causes the fan to stick on. Temperature sensor? Short in the wiring somewhere?
Has nobody had this problem before?

 

[felix_kentish]

I've done alot of reading into this problem and it is very common among golf's and other cars based on this platform. Usually it would be due to the resistor burning out in the fan but I have checked the fan operation and it does work on both hi and low speed (checked by giving 12V to the fans directly). The VAG-COM has not thrown up any fault codes to do with the fan control module. The fans also still work in sync i.e. when the coolant fan is on slow so is the aircon fan.

I can't remove the connector to the thermo-switch on the radiator to check if it's that. Any tips on removing it?
Is there any other sensors that activate the fans?