Strange issue

[NC53]

Ok, so our 2009 1.8TDCi Connect has developed a starting fault which has got us stumped.

Sometimes it will start no problem at all. Other times, the ignition lights come on but it does not crank the engine. If you leave it 5 mins and try again, it springs into life. It does it both from cold and when hot.

No fault codes are present.

I initially thought it was the starter motor but after changing it, the problem was still present. I then changed out the ignition switch but again it made no difference.

Also had a new key cut and programmed in case it was the transponder but, again, it made no difference.

Anyone else had the same issue and what was the fix?

[NC53]

Eventually tracked this down to the grey multiplug next to the battery tray (see pic). One of the wires was partially broken, meaning it wasn't getting a consistent live feed on the starter motor solenoid.

Hope this helps someone else with the same problem.