engine not cranking when cold

[stevegi]

hi i have a c220 cdi 2007, recently it will not start when cold , on turning the key the glow light dosn't come on and the cooling fan runs at full speed, and it will not crank the engine, if i leave it like this for a while on turning the key on and off a few times the glow light comes on and she starts ok, later in the day when its a little warmer, she shows no symtoms of any fault at all and starts ok, i took the car to an autoelectrician who checked every thing he could and couldnt find the fault, the battery is new, the ecu and fuse boxes are clean and dry , any ideas would be greatfully appreciated,

 

[brucemillar]

I would suspect a poor earth or starter relay. Check that your battery earth is clean and tight at both ends with no rust or gunk coating it. I am not sure where your starter relay is located (somebody will be along who can help there) but worth pulling that out and cleaning all the contacts.