2003 Vauxhall Vectra electrial problem

I am having an electrical problem with my vectra, but my fuses seem to be fine, my clocks are failing when i hit a bump on the road, when the clocks fail the Electro-hydraulic power assisted streering (dont even know what it means)light comes on when this light appears the car will not start for approx 10 mins, also when clocks fail the Traction Control system and Engine electronics and also the brake and clutch system lights come on, I have brought the car to a number of mechanics to plug the car into a computer to see what the fault maybe and it just wont come up it wont read it atal.