just replaced xyz which on D2, need help

[ctckte]

i have and 03 disco 2, the other day the sport/manual light lit up and it died, at a red light was able to start it back up and drove it home, the next morning the the S/M light disappear and it start up and ran fine, but a day after that the car wouldn't start so i replaced the xzy switch (gear position switch). After replace the new one the car would not even crank over.
I also forgot to mention a also replaced the battery with a new one. please help