05 e320cdi No start/crank

[wallbenz]

Just started couple days ago

GP lite comes on after 2-3 second delay when turn key to correct position.
Car starts

Yesterday-- GP never came on after 2 starts as mentioned above ( GP Delay)
Car would not start or even crank... as if zero battery

after several trys-over 20 minutes... w no GP lite coming on ,,, finally -delay GP lite- and start. Red battery symbol /visit workshop appeared.

drove home and turned key-- no GP lite/no start.

Started car next am on 2nd try ( 1st try no gp lite)... Battery was 12.3V prior to start... tested while running... held steady 14.0 V at idle.
Tested aux battery after 10 minutes idle... 13.0 V

ANY ideas out there??? Anyone experience the NO GP lite?

FYI- replaced both batteries and all Glow plugs within last 13 months