88 90 - rad fan wont turn off

Ti Kan ti at amb.org
Mon Dec 23 10:28:10 EST 2002

j fizz writes:
> my fan's so rad it wont turn off.. [ahem =]
> is this usually the multi-function temp switch thingie? my temp gauge has
> been intermittent for a while now [which im pretty sure is related to said
> temp switch thingie], but i havent gotten round to digging into it.

No, the radiator fan is not controlled by the multi-function thermo
sensor.  It has its own thermoswitch located at the radiator.  Also,
having the A/C compressor on will also run the fan at low speed.

Make sure your A/C is off, then, unplug the electrical connections to
your radiator thermoswitch, and if the fan turns off, then your
thermoswitch ist kaput.  If the fan still runs even with the switch
disconnected, then the radiator fan relay is probably stuck on.

Your coolant temp gauge, on the other hand, *does* use the multi-function
thermo sensor.  So if the gauge is erratic, there's a good chance that
sensor is also on the blink.

2003 A4 1.8T multitronic
2001 S4 biturbo 6-sp
1984 5000S turbo
1980 4000 2.0 5-sp
    ///  Ti Kan                Vorsprung durch Technik
   ///   AMB Laboratories, Sunnyvale, CA. USA
  ///    ti at amb.org
 //////  http://www.amb.org/ti/

More information about the quattro mailing list