C220 intermittant starting problem

[mrelephant]

My 2003 C220 Cdi has developed an intermittent starting problem - when this happens all the lights etc come on but turning the key produces nothing but silence. After a while (last time overnight) the car then starts normally. My Merc shop has checked the car and the Star diagnoses quick test and engine live data do not show up any faults. Does anyone have ideas as this problem is making the car unusable.

 

[Alex Crow]

Ideally it should be tested under fault conditions, starter relay and starter motor must be top suspects.

 

[mrelephant]

Thanks - problem is it refuses to fail when at the workshop.

 

[Alex Crow]

The starter relay is pretty cheap, a good place to start.

 

[astamir]

Check the key or take it to an electrician