I sometimes have problems starting my 2003 Ford Fiesta Diesel.

When I turn the key it'll either start normally or just start to kick over then die. If I try again, the same thing happens. My battery is good, replaced not long ago.

I can sometimes get it going by turning the key just till it's about to turn over and pull back - I do this twice and then turn the key fully. Sometimes that works - sometimes it doesn't.

Any ideas? My friends think it's the starter motor, but 8/10 times I'm fine.

  • 2
    I'm wondering if the battery cable connection needs to be sorted. Sometimes if there is corrosion buildup on the battery cables (at the battery), it can sometimes work, sometimes not work. Do you find that when it doesn't work, everything goes black (all lights out - some lights will go out normally when you turn the key, others will stay on but may become a bit dim ... I'm asking if all lights go dark)? Mar 17, 2015 at 15:52
  • 1
    Loose connection at the starter motor was my first thought. Check all your electrical cables.
    – jscs
    Mar 17, 2015 at 18:52
  • @JoshCaswell ... ayup. Mar 17, 2015 at 20:38

1 Answer 1


If your starter motor is working 8 times out of 10 then you probably need to replace it. It very likely has developed a dead spot on the armature. If the armature is positioned so that the brushes land on a dead spot, it won't start.

Brushes are the electrical connection between the power source and the moving armature. The picture below shows how these brushes rub against the armature. All of the rubbing eventually causes enough wear that the connection becomes unreliable. (Picture from PontiacBonnevilleClub.com Illustrated Starter Tech 101.)

enter image description here

Sometimes this can be temporarily overcome by tapping on the starter motor case so that the electrical connection is good enough to move the armature past the dead spot so it will start when you try it.

In your 8 out of 10 times, the starter motor isn't on a dead spot, so it seems to work fine. You will eventually find out that tapping doesn't work and you will need a tow to the mechanic. It's better to fix it before that happens.

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