Thanks, The DL1 is about 18months old, Serial on front. I dont think the 12V is particulary bad, have another data logger running with out problems. Have used 3 different CF cards, most recently an industrial spec card for high reliabilty applications, same with all 3 cards. How do I start a support...

I often find that me DL1 has stopped midway through a run, the indicator LED show still logging but it will not respond to a stop logging request, the file on the CF card is corrupted. This normally happens on the run with my best lap of the day ! The DL1 is wired direct into the car 12v, any ideas ...