shouldn't my fans be coming on??

[volks88]

lately when i stop in traffic or turn my car off after it gets hot the temp gauge will rise. when i start moving again it drops back to normal. from what i read in searching it never drops into the cold so i was ruling out t-stat. what i want to know is if my fans should be coming on when i turn the car off? i tought i remember them used to coming on. i noticed that they dont anymore. so yesterday i let the car idle with the ac on to run the fans and it didnt flucuate at all. tb/wp/t-stat was done like 45,xxx ago

[highPSI-S4]

lately when i stop in traffic or turn my car off after it gets hot the temp gauge will rise. when i start moving again it drops back to normal. from what i read in searching it never drops into the cold so i was ruling out t-stat. what i want to know is if my fans should be coming on when i turn the car off? i tought i remember them used to coming on. i noticed that they dont anymore. so yesterday i let the car idle with the ac on to run the fans and it didnt flucuate at all. tb/wp/t-stat was done like 45,xxx ago

Yeah it is suppose to come on. Mine did when i had one.

[volks88]

radiator fan switch maybe??

[volks88]

radiator fan switch maybe??

oh and where is this located? thanx

[volks88]

either im searching the wrong place or im an idiot. i cant find shit on this. anyone?

[skunkoncrunk]

Mine does this sometimes too.

[JayyyyyC]

Mine has never done this except for the time I drove through the back roads with the ac on strong. It only went up a little though.

Sometimes when I turn the car off after a hard ride, then turn it back on a few minutes later, the temp needle is past the middle mark as well.

[volks88]

Sometimes when I turn the car off after a hard ride, then turn it back on a few minutes later, the temp needle is past the middle mark as well.

yeah its not even after a hard drive. it has been hot but its never done this before. still maybe thinking of the fan switch but i have no idea where its at.

[s2the4]

fan control module might be shitting the bed if not already there. That is what tells your fan to either run or don't run. My AC fan has been constantly running for the past year due to a dead FCM. So I have the complete opposite of what you are saying.

[volks88]

fan switch changed and no fans kicking on any way to check to see if its the fan clutch or the fan module?

[volks88]

so when i turn on my ac now the fan will come on for 20 seconds and then shut off allowing the cars temp to rise a little. shouldnt it stay on the whole time the air is running?

[AudiSportB5S4]

yeah for sure. when the AC is on your fan is on with it... maybe some sort of switch that went bad ?

[volks88]

^^ thats what i thought. if its at idle without the air on, their stopped and the temp rises. when i turn the air on, they spin for 20 or so seconds. after they stop i can turn the air off for a few seconds and then turn it back on and its the same thing, they run for 20 seconds then shut down. anyone?

[jakecro]

sounds like your A/C fan is going out on you. Same thing happened to me and I just replaced the fan itself with a unit from a B5 A4 1.8t. I did have to rewire the 'new' fan since the plastic connector was different but it works fine. The replacement is the same part with just a different connector (p/n off by one letter). You could use a direct replacement but at ~$230 I opted for the used A4 unit for ~$50.

Check out my links here for more info (at top of list)

Hope this helps and feel free to ask more ?

[nateS4]

Did you try looking @ the Thermo switch and have you tested the fans by unplugging them and giving them power? Oh and the Thermo switch is in the lower hose near the radiator.

[mrpeterparker]

RESURRECTION FROM THE DEAD.....sorry


has there been a definite answer to this problem? I have the exact same symptoms.

Or is there a good checklist maybe to start checking off?

[wdbdy2000s4]

To start, you can see if there is an issue with the electronics. Use a volt meter to see if the fan motor is getting power when the AC is on, see if the FCM is getting power.

[mrpeterparker]

works when A/C is on

[wdbdy2000s4]

see if your FCM gets power when the car is off. Just to give you an idea of what you're looking at, here is a pick of a B3 passat fan wiring diagram. It will obviously be different but this shows how many switches/relays/fuses are used in a typical vw/audi system.

[mrpeterparker]

k.. i'll dig at it after work here ...

[mcjim]

My car did the same thing when I had a nice sized leak in my coolant after run pump. New pump, problem gone. Dont really know if its related though????