# Cooling fan low speed not working



## 03 jetta GLI (Sep 27, 2006)

Noticed this awhile ago, when idle i would hear the fan kick on high then turn off. This would repeat, though i never thought the slow speed was inop until i found my a/c not blowing cold. Which i never use anyway, what are sunroofs for.








Well I checked fuse 16, 25 and s180 with no avail. Could the coolant temp sensor be to blame? 
I've searched, but what i came up it the 1ohm resister goes bad in the fan or something. I need Some advice on what to do with this problem, who has experienced this?
Thanks


----------



## apstguy (Apr 3, 2006)

Please read the DIY/FAQ, read the Common problems thread where this is explained. If the a/c isn't coming on, it is a fuse. A lot of times the fuses on top of they battery look fine, but are not - test continuity and resistance.


_Modified by apstguy at 1:21 AM 8-6-2009_


----------



## 03 jetta GLI (Sep 27, 2006)

*Re: (apstguy)*

Like I said the fans LOW speed is not working, fuses checked out.
Have two of these 100w 1ohm resisters on the way from
http://cgi.ebay.com/100W-1-Ohm...wItem 
In order to do this mod
http://forums.vwvortex.com/zerothread?id=3890491 
Though there is no pictures for diy.
I then proceeded to find this 
http://website.lineone.net/~al....html 
which actually has some pics to follow.
Also found circuit diagrams on.
http://www.nime.co.uk/content.php?mk4fans 
Once the pieces get here I'll post up how it goes, Hope some of these links will help if some people that are in need.










_Modified by 03 jetta GLI at 2:44 AM 8-7-2009_


----------



## 03 jetta GLI (Sep 27, 2006)

*Re: (03 jetta GLI)*

Well, problem solved.








Low fen speed works!








A/C actually blows cold!


----------



## Zuber Speed (Oct 7, 2001)

*Re: (03 jetta GLI)*

bringing this back..
replacing the FCM would be just as effective correct?
I really dont like splicing electrics on VWs
My a/c blows cold and high speed fan works, but low speed doesnt
Most, if not all pics are dead to all DIYs i found


----------



## diesector (Apr 14, 2004)

*Re: (Zuber Speed)*

Let me know what you find out. I am having the exact same issue. Mechanic wants to charge me $606 to fix. Thanks.


----------



## apstguy (Apr 3, 2006)

No, the fan control module is NOT the issue here. The resistor in the fan motor itself disintegrates after time and wear causing the low speed to no longer function. You bypass the low speed by putting a resistor between the low speed output on the FCM and the high speed input on the actual fan. The DIY explains all of this.
Directly from the FAQ/DIY:
The cooling fan's low speed die caused by bad resistors in the fan motors (which is probably why the above fuses pop). You can just replace the fans or fix the design flaw by either adding external resistors or adding a PWM controller (new VWs have PWM controlled fans) Fan low speed remedy and why it happens: http://forums.vwvortex.com/zerothread?id=3890491
More low speed info (see bottom post): http://forums.vwvortex.com/zerothread?id=3844295


_Modified by apstguy at 6:25 PM 8-25-2009_


----------



## 03 jetta GLI (Sep 27, 2006)

*Re: (apstguy)*

I have a few pics of what i did, i used an old Pentium heat sink to mount the resistors to. Now I'll have to find my camera and upload the pics.


----------

