Need Help -82 300D Dead

[sperry]

Thanks in advance.Last night I replaced the drivers side headlight.After replacement(pretty routine ) turned headlights on to check hi/lo beam & all worked well.Next I turned headlight switch off ,got in & turned ignition switch to start & noticed no glowplug light,radio or anything else came on.Removed key from ignition,tried again with no luck.Removed battery cables from battery,cleaned then reconnected.Battery voltage is @ 13vdc.Tried jumpering from anther vehicle & nothing changed.Would appreciate any suggestions on where to start diagnosing.