DWB

Can someone help with how to properly test the cooling fans when out of the vehicle (2000 TT 1.8 Q).

Each fan has a brown wire, red/blk wire and red/wht wire. I know the brown is ground. When I apply 12 volts to the red/blk wire the fans turn on. When power is applied to the red/wht wire I get nothing. Same for both fans.

Is that normal function? Or should I get something with power to the red/wht wire?

Thanks for any help-- I want to make sure the fans are working properly before reinstalling them.

Thanks
DWB

RussAdams

The fans (V7 and V177) are supposed to be two speed. They should spin slower when connected to the wire with the resistor (red & white), and faster when power is applied to the side without a resistor (red & black).

It sounds to me like your resistors are blown.

See the attached EW28 wiring diagram. The full wiring diagram and how to read the symbols is available in the Bentley manual.

Color codes:
ws=white
sw=black
ro=red
br=brown
gn=green
bl=blue
gr=grey
li=violet
ge=yellow

I'm VERY new to Audi's and just bought my first 2001 Audi TT last week. So take my advice with a large grain of salt!

Hope this helps!
Russ

DWB

Hi Russ-

That's exactly what I thought. I have the Bentley manual and studied the same diagram. Thanks for the confirmation. Much easier to replace the fans since they're out! I found a few for $60 or so each. Cheap compared to what it takes to remove them again.

Unless anyone else has a different idea, it's new fans all the way around!

Thanks Russ--
DWB

RussAdams

Alternatively you could replace the resistor.

With a higher quality one.

Resistors are CHEAP. Certainly not in the $60 range.

RussAdams

I had this issue and conversation a couple years back on a 2000 Mini. I resolved my low speed fan not working by replacing the resistor OUTSIDE the fan box. I put it inline on the feed to the low speed setting, with the theory if it happened again I'd be able to just swap the relay without having to pull the front off the Mini to get at the fan again.

Sold the car before the resistor went a second time.

RussAdams

I was in Ireland when I did the fix on the mini. I'm back in the States now, but poked around the VW sites to find a similar fix.

Cut to the chase, here's how to do a fan RESISTOR fix:
This fan repair modification was developed for a 2002 model V5 Golf, it will probably be OK for other Golf models especially the V6

And here's a long thread of people who have had the same problem of low speed RESISTOR being burned out and what they did:
FAN PROBLEM - POLL SYNOPSIS - MkIV (Mk4) Golf & Bora - uk-mkivs

Hope this helps!
Russ

Mister Bally

The OEM one is a control module that looks like a large relay. Dealer price is about $190.00 On line sources for an OEM part are a bit less. The Chinese junk knock-offs are about $40-60 each but almost all have reviews of barely lasting a few months.

Why risk it? If they don't last I'd bet one will start a car fire taking the whole car out. No thanks. Bosch engineers and manufactures nice stuff.

RussAdams

I'm not sure which part you are talking about... I'm talking about the resistor that is part of the fan, not a control module.

He said his fans are out of the vehicle and that applying power to the low speed side nothing happens. But applying power to the high speed side runs the fan.

IE the resistors are shot in the low speed feed to the fan. The fan itself should be good for years more. Just run a new resistor like the articles I linked to.

I do agree that putting in a cheap fan is going to go badly. But I've also read that replacing with 'new' Audi fans you're lucky to get a year out of them.

10 bucks will replace the bad resistors.

That's what I'd do. But it IS a hassle to pull the fans in the first place...

At least he has choices! Have fun!!!

(I pick up my TT tomorrow)

RussAdams

My apologies!

Multiple times I used the word 'relay' when I meant 'resistor'.

The correct cheap and easy fix is to replace the burnt out RESISTOR with a good quality resistor mounted to a good heat sink.

Sorry for the confusion!!!

DWB

I appreciate the discussion and suggestion to just replace the fan resistors-- I do like fixing only what's broke! However, in my research to find parts, these fans be purchased after market so darn cheap-- less $50 each-- I'm just going to replace the both fans with new. It seems like good insurance for the future and way less time. If I was retired and had lots of beer, I'd just do the resistors ;-).
Thanks again!