# Large radiator fan not working



## green_eg_hatch (May 3, 2010)

As it says above my large radiator fan is not working which is a possible cause to my car getting a little hotter than it should, now o guess I'm trying to figure out what makes that fan come on and what will make it not gone on, could it be the Redon why my car is running so hot. 

Another thing is when I squeeze my rad hoses I don't see the coolant resivour level go honor down.. Should I? 

I recently did the thermorstat water pump, timing belt and radiator cap if that helps any

Thank you


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## radlynx (Jan 4, 2007)

Those fan have slow and fast speed setting. which one in the big fan doesn't run? the slow speed or high speed? I think the first step is to test both your fan thru the fan switch. If you unplug the fan switch (triangular shaped connector - 3 wires). 1 of this wire is a live positive wire. Here's what you can do.

1. Find which of the wire is live, use a tester. Let's assume it's Wire A.
2. Switch on your ignition key (do not start).
3. Short wire A to wire B (both fan should run either slow or fast)
4. Short wire A to wire C (both fan should run either slow or fast)
5. if one of the fan doesn't run after step 4, replace that fan. (would be best to replace both so you just have to do it once)

i hope this helps and let me know what comes up.



green_eg_hatch said:


> As it says above my large radiator fan is not working which is a possible cause to my car getting a little hotter than it should, now o guess I'm trying to figure out what makes that fan come on and what will make it not gone on, could it be the Redon why my car is running so hot.
> 
> Another thing is when I squeeze my rad hoses I don't see the coolant resivour level go honor down.. Should I?
> 
> ...


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## green_eg_hatch (May 3, 2010)

thank you i will begin testing on friday, neither of the speeds are working on the larger fan, what makes it come on?


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## radlynx (Jan 4, 2007)

it comes on when the A/C is ON. it comes on when the fan switch reaches above its operating temp. it should come on when your gauge temperature goes above 190.

Three things you need to fix or check or replace in order at a time.
1. Auxiliary Fan
2. Fan switch (located in the bottom of your radiator on the driver side - this provides power to the fan in hi or low speed depending on the coolant temp)
3. Fan control module (located under your battery - accessible in bottom - remove bumber to access better) - this controls the fan - if defective, all the rest above may not work or intermittent.

Try to leave your car idling and watch your gauge in the dashboard, at some point in time the fan should run, if it does not run and your gauge goes above 190, that specific side of the fan is defective. 



green_eg_hatch said:


> thank you i will begin testing on friday, neither of the speeds are working on the larger fan, what makes it come on?


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## Big_Tom (Aug 19, 2007)

just buy a new one. if the small one works and the large one doesnt then just buy a new fan.i recently replaced mine with one from ECS. works and fit great 

http://www.ecstuning.com/Volkswagen-Jetta_IV--1.8T/Engine/Cooling/Fan/ES2091148/


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## green_eg_hatch (May 3, 2010)

big thomas. that fan is for auto only for aww and awp right? i have a manual so im unsure if that will work or not on my car


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## ColoradoSoul03 (Sep 14, 2006)

My fiancee's 03 Jetta is having the same issue. The small passenger side fan runs normally but the large driver side fan is inop in both high and low speeds. Does anyone know which wire is high, low, and ground for the fan itself? I suspect the fan motor but I want to check it first.


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## green_eg_hatch (May 3, 2010)

i just bought a new one and it worked. but today the motor went up on the new fan... feel like im taking 1 step forward and 4 backwards


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## Big_Tom (Aug 19, 2007)

green_eg_hatch said:


> i just bought a new one and it worked. but today the motor went up on the new fan... feel like im taking 1 step forward and 4 backwards


 damn u must have a short somewhere. i'd be pissed about the wasted money 2


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## radlynx (Jan 4, 2007)

Looks like you need to test your Fan Control module. Are you saying that your new fan (low speed and high speed) is not working? It could be that your new fan is defective too. If there's a short somewhere, your small fan should go out as well. Try to have that new fan replaced under the warranty.



green_eg_hatch said:


> i just bought a new one and it worked. but today the motor went up on the new fan... feel like im taking 1 step forward and 4 backwards


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