swedishaudi

I am a new TT owner. I recently bought a 2002 TT Quattro that overheats when run at load for any extended time (ie. over 2 minutes.) I have noticed that the left side radiator fan doesn't run at all (even with the AC on.) The right side radiator fan however does run. I have checked the fuses and they all seem to be operational. I am thinking that it is either the thermal switch in the radiator that is bad or perhaps the left side fan itself is bad.

Any thoughts from any more experienced TT owners out there?

RM879

Swedish, this happened to my '01 TT Quattro. A question, when you say left are you referring to Driver or Passenger side of the car? Because I would not recommend these instructions on the passenger radiator fan. *Warning* if the fan does engage it will spin up fast enough for injury to occur so this is at your own risk. The way that I figured out it was the Drivers Side radiator fan was by turning the car on, turning the ac on, walked around to the radiator fan and manually spun it from the top flat edge, keep in mind that you need to move your hand away fast!!! My fan would engage for about 10-15 seconds and then stop spinning again. I replaced the fan and took the old fan apart to find the fan blade was stripped and not engaging with the motor. Hope this Helps.

swedishaudi

It is the driver's side radiator fan that is not running. The passenger one seems to run just fine. Thanks for the help - I will try that trick and see what happens.

monkeytronic

I've recently come across a similar issue with an '01 TT 225 where its main rad fan wouldn't turn on yet its secondary fan would switch on normally with the A/C.

I found that if I pulled the 10A fuse #16 in the dash fuse block, both fans should turn on with the ignition on. That's the fuse for the fan control module. If both fans don't turn on with said fuse pulled, either one or both fan motors or the fan control module itself is faulty.

swedishaudi

I tried both 1) pulling the fuse in the dash panel for the fans and 2) manually spinning the driver's side fan with the ignition (and AC) on and still nothing. This makes me think the fault is in the driver's side radiator fan and not in the fan relay box or thermal switch.

Or is there something else I should be checking? If not anyone know where to get a good replacement fan?

monkeytronic

It is possible to jump the fan motor directly to test it. Both fans have a 3-wire connector each that terminates at the driver side base of the radiator. Disconnect the connector of the suspect fan in question and note the connector's outer terminals and their associated wires: one with a red with black stripe wire (+12V) and one with a brown with black stripe wire (ground).

Insert a pair of short leads terminating with either male or female spade connectors (both fan connectors should have opposite genders so that they can't be swapped). Minding correct polarity, hook said leads up to a set of jumper cables which are then momentarily connected to the car's battery. If the motor doesn't spin up, you've found the culprit.

BTW it is possible to unbolt and carefully snake either fan up and out from the back of the radiator cowling without first having to remove the bumper cover and unbolt the radiator for clearance.

DuTTch Quattro

It is either the sensor in the rad or the fan control unit the passenger side fan will come on if the AC is on,if it doesn't it's the fan control unit. Mine went and blew out the fuse block on top of the battery as well.its a real awkward repair changing the sensor.

odachimaster

this is becoming a real problem lately with the MK1 TT and the VW Jetta/Golf 1999-2003 as the

AUX. controller unit has been going out alot..... I was going to ask if you had checked the battery top they take 30 amp fuses .... but when the fan comes on it pulls 3 amps and tey actually only have a 3 amp to handle it and

after time it wears down so I ran a wire with a 10 amp breaker in-line so no damage would come if the surge was to much for the regular 3 amp

I have not taken a picture of it yet I will try for Sat the 17th and post from where to where.


I also have a set of BRAND NEW FANS JUST OPEN TO MAKE SURE NO DAMAGE IN SHIPPING just FYI

L8T......

speeedfreak

You can run 12v to the fan and it though it may run w/ direct power it could still be bad. Both connectors are right beside the driver's side of th radiator if you decide to do so. "Yes" you can remove the fan w/ shroud w/o removing the bumper cover and/or etc. I say that it is either the fan or the fan control module. I would replace the fan.

swedishaudi

My next questions:
Will the driver side fan fail to kick on if the water pump has failed?

How can I determine if the driver side fan is the culprit rather than the water pump? It does not overheat at idle but does under minimal driving. And by overheat I mean the dash gauge approaches "H" and kicks in the digital coolant warning light too.

Or is this a dash instrument cluster issue? Shouldn't the driver side fan turn on even if it is a cluster problem?

Thanks for the help.

BTW - I replaced the thermostat thinking that might have been the issue too but that solved nothing.