W209 270 cdi alternator issue??

[Benz270cdi]

Hi all I was wondering if anyone can shed some light on my problem please? When starting up from cold the alternator is not charging battery visit workshop illuminates on dash, if you idle/ drive until the engine begins to warm up , turn the engine off then back on you can hear the alternator kick in and it charges at 14.5 volts any help much appreciated thanks in advance

 

[Benz270cdi]

Anyone have any ideas please?

 

[grumpyoldgit]

Could possibly be the pulley. These alternators are fitted with a clutch pulley I believe and if it's starting to fail it could be catching when it's warmed up. (Only a guess though).

Have you searched through the posts on here?

An example on ebay......
MERCEDES CDI Alternator Clutch Pulley (ZEN BRAND) | eBay