[s-cars] Fan works,

[Tom Green]

Slow down a little here, Jim.  I would tackle these one at a time.  I  
know you need to get any parts ordered, so that sort of depends on  
your confidence in these parts.  The MFTS seems to be doing its job  
reporting to the coolant temperature gauge.  I would check the  
contacts under the rubber protective boot to make sure they are not  
corroded or otherwise in bad shape, or the sensor leaking.  It could  
be coated with deposits from the water inside.  Same with the  
connector for the coolant tank level sensor.

I echo the comments of Scott J, FWIW.  If the radiator is original, it  
is common to see hard water deposit sludge completely covering the fan  
sensor.  If shorting the sensor wiring contacts produces results, it's  
time for a new sensor, and IMO,  a new radiator.

Tom '95 S6
          '95.5 S6 avant
Knoxville, TN

On Saturday May 18, 2013, at 11:53 AM, "Jim Fleischer" <jim at almgt.com>  
wrote:

> Alrighty then!  I may have misunderstood something earlier regarding  
> some testing, but.....
>
> Was able to get the fan going at both speeds jumping the terminal  
> wires from the radiator sending unit, so looks like I'll be  
> replacing that.  However, Scott mentioned something about the MFTS  
> triggering the overheat warning and suspending A/C operation.  These  
> are my symptoms as well.  Could both have stopped working at the  
> same time, or one take out the other?  Or is it just the MFTS  
> malfunctioning?  Am I best off just replacing both?  Besides the  
> usual AutohausAZ, GenuineVWAudiparts, etc, any good source?  Thanks!
>
> I'm sure there are other things I should replace while I have the  
> coolant out.....I've got a couple of plastic coolant fittings, etc.   
> Feel free to chime in with other suggestions.....
>
> Thanks for all the help and patience.....I learn something new  
> everytime!  Totally appreciated!
>
> Best regards,
>
> Jim Fleischer
> '95 urS6 avant
>  ----- Original Message -----
>  From: Qshipq
>  To: Jim Fleischer ; s-car-list at audifans.com
>  Sent: Friday, May 17, 2013 10:12 PM
>  Subject: RE: [s-cars] Fan works, just doesn't come on.....(Formerly  
> Electric Fan not working)
>
>
>
>
>  Pull the belly pan and look for the temp sender on the DS radiator  
> end cap.  Pull the 3wire connector off temp sender.  On the wiring  
> plug side jump positions 1-2 med speed fan then 1-3 high speed fan.   
> If this operates the respective fan speeds replace radiator sending  
> unit ---  you describe classic radiator fan switch failure. If you  
> have an overheat warning the a/c should shut down which means the  
> aux fan is also shut down.  IIRC on the S-cars that overheat warning  
> is triggered by the MFTS and/or low coolant level - that circuit is  
> T'd together.
>
>
>  Could be the MFTS is bad too...  Or because your rad fans aren't  
> functioning the MFTS is actually doing its job?
>
>
>  Bet this car fails the rad temp sender check.
>
>
>  HTH
>
>
>  Scott J