Vauxhall Astra engine wont start

I have brought a vauxhall astra and it wont start. I have had to replace the radiator pack as it was leakin. The car will crank over but will not start. The car has fuel and it is reaching the common rail and is being fed to the injectors. The only real issue i can see is that the harzards flash when i put the key in the ignition. Could this be the problem? Can someone please shed any light on the situation?