Recently changed engine on my girlfriends 1.4 Corsa 2002. Now after a ten min drive I turn of engine & it won't start. I wait ten mins it starts. All dash lights light up but engine won't start. I also noticed when touching the accelerator the brake light in the centre of tailgate flicker on & of. There is also a drain on battery leaving it flat not completely but not enough to start. Can some one please spread any light on this. Thank you.