You certainly do not need a 14 volt battery for your car. I had a 300CE Euro and it had the normal 12 volt Bosche in it ( capacity I cannot recall ) I would be interested to hear who in Dubai is doing the troubleshooting for you. Might I suggest you call my people in Rashidya who certainly know heaps about Mercedes cars and they look after mine very well indeed. Call them on 04-2852800, ask for Ben and good luck !

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1993 190E 2.0L (Euro.) sold
1991. 500 SEL (Euro.)
1991. 300 CE (Euro.) sold
1993. 500 E (U.S. spec.)