hi guys need some help i have a S class 320cdi had it for a few months the problem is that when i start the car in the morning on some days it doesnt start the cluster lihts go dim on accaions and some times its ok for a month and some times it will happen every four or five days it only happens in the morning . brought new battery thinking it was the battery but if u take out the battery and put the charched battery its ok. so i recently checked the battery life of the one i took out and it showed it was still full bit confused yet it didnt start.i took to garage got checked but could not find foult. only happens when its a cold morning very confused need help i was told to drive car more may be not driven enough but the problem is still there please help driving me mad