Fan Fix
Decided to finally get my arse into gear with regards to sorting a
problem that I have got on my car with F*cked resistors in the rad fans. This is a big
problem for MK4 platform cars which is explained in more depth
here but the short and sweet of it is that the slow speed fans don't work . Slow speed fans should kick in between 92-97 degrees but if the resistor is burn't out then they won't kick in until between 99 - 105 degrees which ISN'T good!
I was going to buy the NIME fan controller which is circa £90.00 but you can make your own for <£25 which does exactly the same thing. Instructions below
Shopping List
1. 2 x 1Ohm 100W Aluminium Clad Resistors. RS Part Number 188087
2. Aluminium Sheet Heat Sink. RS Part Number 434043
3. Heatsink Compound - I'm Using Artic Silver computer compound
4. 4 x 60CM lengths of cable (>1.5mm2)
5. Heat shrink
Installation Instructions (courtesy of Alan Lorely)
1. Locate appropriate mounting point for heat sink close to the fan control module and drill mounting holes in heat sink.
2. Smear heatsink compound to back of resistors and secure to heatsink with nuts and bolts.
3. Solder a length of wire to each end of the resistors and heat shrink.
ASSEMBLED HEAT SINK
4. Mount heathsink and check that nothing will be chaffing against any wires or cables.
5. Cut the RED/WHITE cable on the FAN SIDE of the connector to the large fan join the cable from the fan (just cut) to one side of a resistor, splice the other end of the resistor into the RED/BLACK wire on the FAN SIDE of the connector.
FAN CIRCUIT (for each fan)
6. Repeat step 5 for the small fan using other resistor.
7. Make sure everything is heat shrink-ed and insulated to prevent chafing.
8. Test your installation using a voltmeter or put on the aircon, (slow speed fan should spin)
WARNING! - These resistors can get VERY hot when working (100c) so allow to cool before touching.
Thanks to Alan Lorely for this
guide (PICTURES INSIDE)
Will get some pics up of my installation soon. Use this info at your own risk, I take no responsibility for any damage you do to your car.