Sorry did not see until now...... can test each fan to make sure power is getting to them... can use just a test light as have had both fans replaced one twice ... we are looking at putting an in-line fuse so it will not take out aux fan controller did that in VW VR6 car... just these crappy wiring guides are a pia..... but check to see if juice is getting to them maybe even hook separate power source up to see if they will run (battery)....

we want a final solution as well... sorry about the delay....

 

thanks NorthD
some update

i changed the fan switch and now my fans kick in when temp is almost at H, quarter left to H....
soon as i turn car off, fans turn off as well
top radiator hose gets super hot, and bottom hose is not hot at all.
thermostat seems to be working fine as i feel pressure at the top hose.
what ever happened to my car, it started a chain reaction where it burned the fan switch and shut off the thermostat..
so given these facts, you guys think its the water pump? I dont know much about cars but im assuming at this point that it is...
any suggestions ?

 

Hi fellow audi owners, iv had a few audi's now and never had the problems im having with one of my cars now. Its a 2002 A6 2ltr petrol, euro spec as i live in Ireland, the rad fan won't work. I noticed the module had been replaced before, i changed coolant temp sensor and thermo fan switch, still nothing. Tried with A/c on and nothing. I noticed the econ is on A/c automaticly when A/c is on. I ran power to the fan module plug and fans kicked in so does that suggest no power to the module. Iv just bought 2 fan relays to try them. The coolant warning light is also staying on. Happened when i had to change coolant flange that holds CTS, do i need diag to turn it off. The car is not over heating when at traffic either. Its really puzzling me. any suggestions

 

this forum doenst seem to be of any help as there are not to many members, but ill try my best to help you, my issue with the fan ended up being the water pump, it wasnt pumping water for my fans to turn on, i changed a few things before i noticed there was a domino effect, at first water pump gave out ( i did not know ) i drove my car and stopped as soon as it over heated, as i had to get home and did not want to call tow truck, i did this 5 times, drive and stop, cool car drive etc. what this did was cause my thermostat to close shut, from there, my radiator fan switch went bad as well, so i changed that also, i did change my relay and put a new one, just to make sure, i also put a new water temperature sensor...all this done, as i mentioned, it ended up being my water pump....

so it could be either your thermostat or your water pump,
check your hoses that run from radiator top and bottom, see which one is hot and which ones have pressure by squeezing them
hope more people could have helped me with my issue, great site but this form is dead

 

Thanks for the reply, well an update on my car is that after changing the coolant temp sensor, thermo fan switch, 2 relays and the 40a maxi fuse + 5a fuse (which were blown) there is still no radiator fan when car gets to running temp. Its not overheating so? ??? I live in Ireland, not the hottest country so maybe its not getting hot enough to kick in. anyway i found the problem with the warning light, after changing coolant flange i never connected the warning light connection under the expansion tank? ?? Whoops. so its down to a faulty thermostat or clogged rad. The top hose is very hot when car gets to running temp, bottom hose is only slightly warm, what does this suggest? remembering that the temp gauge gets to 90c fairly quickly from cold start but not really overheating in traffic? Also would like to know exactly where thermostat is on my car? I've changed water pumps on my other cars A4's and don't remember the thermostat being removed to get to the water pump ?

 

hmm, it could be a clogged radiator, but im a bit lost, now does your car overheat or it does not? you mentioned it does then you said it does not??
also have you changed your water pump before? also how many miles does your car have?

 

one more question, does the top rad. hose have pressure on it when the car is running, meaning if you squeeze it, is it stiff or can you squeeze the hose with your hand, another words, is it limp or hard..

 

i don't know if the water pump has been changed before but the car has 125k miles on it and is starting to overheat in traffic, ok when moving,

 

lol, you would have to buy me dinner at least before i could answer that I, but seriously, im not sure only that it gets really hot and bottom hose cold. The expansion tank has lots off pressure if opened after a drive ?

 

lol no pun on that last statement,
well if your water pump has not been changed after 125k, be sure it will go bad verysoon if it already hasent, so get that replaced asap or you will blow your engine.
i would get the car checked out asap if i were you before you run into more issues.
but for the looks of it, its either your water pump or thermostat, i dont think your rad would be clogged, but that would be my 3rd guess.