Recently my 380 was being jumped after a dead battery, when the cables were attached sparks were visible from the alternator. I immediately disconnected the cables. When the battery was recharged and the car started the ABS indicator dash light is visible and the radio does not now work, Is this a overvoltage relay problem or several problems.

First just replace the overvoltage relay if the fuse in the top of it alone doesn't fix it. Also it sounds as if you either blew a fuse or killed the radio.
Good luck

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM