2003 sl 500 wont start

[vinc68]

hi guys

a buddy of mine have bought a 2003 crashed sl500. we have rebuilded the car started it and it ran great . we drove it to the paint shop painted it but now the car will not start . i turn the key on all the displays work but i cant start it . when i turn the key on the engine cooling fan start and run full rpm fot about 1 minute . i have tried the start button on the shifter and it dont work . i know the starter work cuz i have jumped the relay in the fuse box and the engine crank but dont start .

i need help cuz i dont know what can go wrong