Morning all. Apologies if this has been posted elsewhere. We have an ML 280 CDI and it has a really irritating battery drain problem. We initially replaced both the main battery and the auxiliary battery with no luck. We then had a diagnostic carried out by a specialist MB garage who stated it was the stereo head unit that was faulty and they wanted £2700 to replace it. Needless to say we bought an after market head unit which was fitted by a specialist (much better than the standard head unit by the way). Anyway, that still didn't resolve the problem. We then had it re diognosed by an independent company who narrowed the problem down to the alternator. Alternator replaced yesterday and then driven for 1 hour to ensure sufficient charge, returned to the car after half an hour and the battery was dead again. If anybody can help with this it would be greatly appreciated and probably save my sanity (and bank balance) Thanks in advance.