Electrical problem
1999 Vauxhall Astra 6 cyl Two Wheel Drive Automatic 40,000 miles

hi my astra wont start,its trying to turn over but wont,the control indicator symbol on the dash is constantly on. when reading the manual it says it should only stay on briefly? if it flashes when turning the ignition its a fault with the immobiliser? but mine does not flash its staying on all the time? really trying to avoid taking it to the dealership as they cost an arm and a leg and it seems as if it could only be a minor problem. please any suggestions or answers would be much appreciated asap.many thanks.