Found fault.Checked 3 wire connection onto aleternator.The middle wire which is blue had no current when plugged out so i traced this wire through loom and found break in wire down back of engine.The blue wire travels in loom across the front of engine over timing belt housing and then goes down the back of engine and turn across towards gear box side where it goes into fusebox.The break in wire was between top of timing belt housing and where loom turns at bottom rear of engine.
Hope this is of some help to someone who has same problem.The wiring in modern cars is very small and tends to break easily .