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    Re: VW Polo 1.4tdi 2002 Archived Message

    Posted by Peter Cooper on December 2, 2008, 2:01 pm, in reply to "VW Polo 1.4tdi 2002"

    The alternator needs to be excited by some voltage. Usualy through the warning lamp circuit.

    If the bulb is blown or not working this will cause the fault you have.

    On the older cars we used to earth out the thin wire at the alternator and see if the lamp came on. This method is no good anymore as some manufacturers put a resistor in paralel with the bulb and if you earth it out it melts the dash
    printed circuit.


    You can test it safely by connecting a snapon test light to earth and on the thin wire at the alternator and if it lights up the bulb is ok and your fault is usualy in the alternator.

    If it dosent light up the faults in the bulb or wiring.


    Hope this helps


    Peter Cooper





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