# [FIXED] Radiator Fan Switch... Easy to replace??



## bmccoupe (Apr 27, 2012)

Did about a couple of hours before searching and even went and tried to access the switch.

Is it easier to remove the front bumper assy as the Bentley states?

What's the best tool to use? And, what size of a tool do i use?, i didn't have anything bigger than a 19mm.

I removed the battery and battery tray to get better access... haven't purchased the switch yet, so i was just playing around.

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*updated* 
Replaced the switch and fan comes at about 96-97C... haven't diagnosed whether or not the 2nd/higher speed comes on at 102C. The switch I installed is not OE Audi, it is the triangular shaped connector one made by Meistersatz.


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## bmccoupe (Apr 27, 2012)

anyone?


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## Hoggy (May 8, 2002)

Hi bmccoupe, As no one as answered, never done it, but it is 2/3rds the way down on the passenger side of rad. 
What symptoms do you have for wanting to replace it.
Hoggy.


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## bmccoupe (Apr 27, 2012)

Hoggy said:


> Hi bmccoupe, As no one as answered, never done it, but it is 2/3rds the way down on the passenger side of rad.
> What symptoms do you have for wanting to replace it.
> Hoggy.


Read almost every overheating thread here and i just changed the thermostat based on reading some threads...

I flushed the coolant and replaced with G12 along with a new OEM thermostat (PIA btw)...

Been using 49C to monitor cooling temp along with Torque (on Android & bluetooth adapter)...

After changing the therm/coolant... car has been running a little cooler than before. However, when i stop the car for a long amount of time in idle, i get up to about 104-107 deg C. After running on the freeway or when the car is moving, temp is around 90-94C.

Noticed that my rad fan had turned on AFTER the car was off, but did not turn on when i popped the hood with engine running (~98C to 106C).

Checked coolant temp with engine off and rad fan on (temp ~108C).

Is this just a matter of replacing the coolant temp switch?? (i already have a green top sensor and don't think it's the water pump as other posts don't seem to align with mine )


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## Hoggy (May 8, 2002)

Hi bmccoupe, Temps will be higher when stationary in traffic, because of no airflow through rad until fans cut-in, but fan should be running @ 102 ish. Engine off & fans running will not really drop the temperature, because there is no water flow around system. Have you checked the links/fuses on top of battery, these are known to corrode & burn & cause intermittent fan running probs. Other parts for the fan control system are below the battery box, remove battery & box for access.
Hoggy.


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## bmccoupe (Apr 27, 2012)

Hoggy said:


> Hi bmccoupe, Temps will be higher when stationary in traffic, because of no airflow through rad until fans cut-in, but fan should be running @ 102 ish. Engine off & fans running will not really drop the temperature, because there is no water flow around system. Have you checked the links/fuses on top of battery, these are known to corrode & burn & cause intermittent fan running probs. Other parts for the fan control system are below the battery box, remove battery & box for access.
> Hoggy.


I checked the green fuses on top of the battery... saw a post here with a useful picture with descriptions of each fuse and cable, so i went out right away and looked at the fuses and holders. They looked nominal.

Fan does not come on even at 110C. At that temp, i stopped the engine, since i didn't want it to get that hot.

I'm about to order the switch today... hopefully, i can replace it myself (and, w/o removing the front bumper).


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## j3roen (Jan 28, 2012)

bmccoupe said:


> Hoggy said:
> 
> 
> > Hi bmccoupe, Temps will be higher when stationary in traffic, because of no airflow through rad until fans cut-in, but fan should be running @ 102 ish. Engine off & fans running will not really drop the temperature, because there is no water flow around system. Have you checked the links/fuses on top of battery, these are known to corrode & burn & cause intermittent fan running probs. Other parts for the fan control system are below the battery box, remove battery & box for access.
> ...


This could well be a fan switch problem but I have one more check to suggest. In my case, the first "speed" on the fans was not working, only the second "speed". (I can't come up with the correct word).

It's easy to check if it's broken; put 12v on the connector. It has 3. One for mass, the other 2 for the different speeds.
It's known problem for serveral TDi's and in my case my TT.

There is a relative cheap fix. Let me know if you did the check and the fan's first speed is broken.

Good luck!


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## nordic (Apr 26, 2010)

Have same problem with 1st fan speed. Did replace the fan switch - access is very bad. And it wasn't a cause... Either the controller or fan itself. Didn't have time to check the fan, but their connectors are at radiator bottom, under the battery. Both fans have 3 wires going in.


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## bmccoupe (Apr 27, 2012)

nordic said:


> Have same problem with 1st fan speed. Did replace the fan switch - access is very bad. And it wasn't a cause... Either the controller or fan itself. Didn't have time to check the fan, but their connectors are at radiator bottom, under the battery. Both fans have 3 wires going in.


Nordic, did you ever fix the issue? if so, what was it?


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## nordic (Apr 26, 2010)

Nope, sorry... The fan kicks in at 110, but as it takes long to get to that temperature, I didn't feel the urgency to get it checked... Since I've got the temp switch replaced, my second call would be to check the fan. If one speed has indeed given up, I think I'll just rewire the 2nd speed to start at both 90 and 110 degrees...


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## j3roen (Jan 28, 2012)

The only way to make sure the 1st speed is broken is to put 12v on it like i described in the post above. It's not really hard; you only need the remove the engine cover.

I had the fans and fan siwtch replaced, but guess what; they burned out almost immediately. Luckily I didn't buy OEM.

The fix was a DIY kinda fix. The guide is in dutch; but you might have some luck with google translate.
http://members.home.nl/brynukoop/ventilatormod.pdf

After this, no problems at all anymore.

Just to be clear; this is no fix for a faulty fan switch (mine was 100% working). It's just a fix for the fan's 1ste speed not working. Basically the fix overrides the broken 1ste speed, and uses the 2d speed but delivers less power and hence a lower speed.

Let me know if I can be of assistance!


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## bmccoupe (Apr 27, 2012)

j3roen said:


> The only way to make sure the 1st speed is broken is to put 12v on it like i described in the post above. It's not really hard; you only need the remove the engine cover.
> 
> I had the fans and fan siwtch replaced, but guess what; they burned out almost immediately. Luckily I didn't buy OEM.
> 
> ...


Is there any way to check using A/C or anything else besides probing and providing power to the fans to see if 1st speed and/or 2nd speed fans are working?

The 'fix' you mention above does not sound like something i'd like to implement--it's almost a last resort type of fix. Also, since you replaced the fans and switches and something burnt them out, doesn't that point to something else?


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## bmccoupe (Apr 27, 2012)

Also, ordered the switch and it will be coming in soon.

Found out that the switch is 22mm... any suggestions on replacement tool to use? Crow's foot + Universal Joint work? Angled box wrench? (Still wondering if i need to remove the bumper for better access or not)...


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## mikec1979 (Jul 31, 2010)

I just replaced my fan switch with the Neuspeed 3 pole switch that brings the fans on at 80 degrees.

It was a git of a job.

Battery out including the box, intercooler pipe off, map sensor disconnected, wiring moved and a deep 30mm socket from Halfords to loosen the switch. The switch is located about 2/3 of the way down the end of the radiator.

It was very tight for space and I've got big hands lol.

It was time consuming because you have to ensure everything is refit properly or you will have to strip everything down again.


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## bmccoupe (Apr 27, 2012)

mikec1979 said:


> I just replaced my fan switch with the Neuspeed 3 pole switch that brings the fans on at 80 degrees.
> 
> It was a git of a job.
> 
> ...


Ok... sounds like you did not remove the front bumper. It sounds like you have a 225 or 3.2. Also, sounds like they are 2 different part numbers with different size switches... the one i ordered is 22mm, but i could be mistaken, and i'll grab a tool to see if it is truly 22mm.


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## mikec1979 (Jul 31, 2010)

Hi yeah mine is a 225.

I idnt remove the bumper, I didnt really see the need tbh. I even had to chage the electric plug wiing too lol.

Arse of a job!!!

The Neuspeed switch was the same size as the standard and as they have to have a socket over where the plug goes in it has to be a deep socket. I got mine from Halfords for £8.


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## j3roen (Jan 28, 2012)

bmccoupe said:


> Is there any way to check using A/C or anything else besides probing and providing power to the fans to see if 1st speed and/or 2nd speed fans are working?
> 
> The 'fix' you mention above does not sound like something i'd like to implement--it's almost a last resort type of fix. Also, since you replaced the fans and switches and something burnt them out, doesn't that point to something else?


There is no other way to check for this. The only way is to put 12volt on the connector.

First I tried switching the fans by non OEM; it almost immediately died. Since the fan switch was replaced by a brand new one beforehand. With the AC switched on, the fans both must be running; regardless of the temperature. You should also see a fan at the AC pump running if I recall correctly. When that's not running with the AC switched on, the fan switch is your best bet.

New OEM fans are expensive and a $%$% to install, you best make sure it's not the same problem I had. Again, it may very well be the fanswitch but I'm just trying to help you diagnose the problem.

Wether or not you chose to replace the fans is of course up to you  It's a known VAG problem; the fans later on where replaced with better quality parts.

Another thing to take note off; even with the AC turned off the temperature hardly ever reaches 90 degrees. Only when I have it running idle, or in traffic, it might reach 102 degrees. When the fans switch on (2nd speed), it quickly drops again. 82-90 is normal working temperature on my car.


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## bmccoupe (Apr 27, 2012)

just got the switch in... bad luck... i got to the switch, removed the connector and it was the triangle-shaped connector. The OEM one i received is rectangular with rounded edges.

I cannot find the part # for the triangular switch... all point to the square w/ rounded edge connector. Does anyone have the part # to the triangular connector fan switch handy? :?:


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## bmccoupe (Apr 27, 2012)

Found the part #...

1H0959481A = triangular connector
1H0959481B = square connector


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## bmccoupe (Apr 27, 2012)

Updated the first post...

Comments on how i did the install...

- Did not remove the bumper
- Removed battery, battery tray
- Removed the fan control module screws; did not disconnect it, just moved it out of the way
- Used a 29mm deep socket (1/2" drive)
- Had the new switch ready and threads lubed with coolant
- Placed a rag under the old switch
- Replaced and re-tightened

If i had to do it all over again, probably would take me under an hour.


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## bbunce91 (Jan 28, 2015)

Hi bmccoupe,

Sorry to revive an old thread but I need to do the same job.

Did you do all of the owrkfrom the top of the engine after you removed the battery etc?

Thanks


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## fertooos (Dec 15, 2019)

Hi bmccoupe, As no one as answered, never done it, but it is 2/3rds the way down on the passenger side of rad.
What symptoms do you have for wanting to replace it.


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## fire88 (Jul 15, 2021)

Hi guys, just done my switch this afternoon, it's not that hard at all if you do it from the bottom of car. 
No need to remove anything just drain coolant.
it's suppose to use 29 deep socket but mine is not deep enough so I used 30 MM socket, went very easy.
in the meantime you can bridge two fans connectors with battery charger.
hope it helps with someone with same issues.


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## Lex885uk (Dec 6, 2021)

HI Guys I know it is an old thread but sill bit of activity so maybe I will try it. I have a 2002 TT the 225 BAM model. And my fans stopped working, even if I put on the AC the fan does not turns on. But I have a sensor issue as well thats another problem what causing the coolant temerature sensor to read faulty 120 degrees so thats kiks the fans in on full speed so the fan itself working for sure. 

Anybody got to the bottom of it? is it the fan temperature switch need to be changed or the fan control module?

So for me no low speed on the fan.

any reply would be appreciated. Thank you


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