Hi
I also have only been able to start my sprinter 1 in 100 attempts of the key, I have changed the fuse and got starter error on the dash when I put the original one back in- no message, still no cranking however.
is this the ecu etc. without the dash message or will draining the system work?

Bob, February 2011

try ign wire on starter the smallest one often just needs taking off and cleaning
check water level as will not start if low

ian, February 2011