Nothing when turning the key to start
 

So....
recently i have been having trouble starting my volvo.
put the key in, turn it to postion II everything comes on, dash lights up warning lights go off as usual, turn the key to start and nothing happens at all most of the time. so i repeat the process until it starts basically keep turning on and off then it will fire up. then on other days it will start on the first turn??
Throught it might be the battery so checked the existing battery it seemed fine, hooked it up to a mains charger and it was charged in 10mins but it still had the same problem, next step was to get a new battery witha higher CCA as the current battery was about 4 years old and does lots of short journeys.
Still got the same problem, the alternator is fine, the connections are fine.
Could it be a relay somewhere??
It seems like when i turn the key nothing tells the engine to start, theres no clicking or trying to turn over it just blank.

2005 V50 2.0D

You can try to hit the starter a little bit next time it does that to rule that out, if it turns right after hitting it a bit, its most likely a starter relay issue.

If starter is not at fault it may be the ignition key socker contacts, CEM contatcs or CEM itself.

Easiest (IMO) is to start by checking the starter out.
Then you can check for ignition key socket, by hitting a bit around it when key is in cranking position.
Also check connections to the CEM under the glove box for loose or dirty/corroded connectors.

Thanks

for clarity what is CEM??

is that what i would call the fuse box with all the relays in it the thing that hinges down under the glove box

Yes you are right, the fuse box under the glove box

It's diesel, yes, if it outside temp dependent ? if it is could be glowplugs.

Turning key on/off a number of times causes the glowplugs to cycle and get hotter.....

its not temp related, even after when the engine is a operating temperature the symptoms are the same,
and its not every time, it started first time the other morning in minus 6 so i've ruled out cold starting problem

Do what HOKS said!

I'd place money on it being this....

https://www.volvoforums.org.uk/showthread.php?t=285582

was a dodgy ignition switch - replaced with a second hand on for £30
starts everytime now