Ok folks whats your thoughts....

Sometimes my PAS starts the wheel twitching (not a lot but you can feel it , especially when turning one sec its heavy, next very light) , the voltmeter is jumping up and down like a silly thing. Happens at irregular intervals. Switching off and restarting cures it sometimes for only a short while, sometimes for a long while.

Please someone tell me its a cheap fix....

dodgy battery ?

faulty sensor ?

dodgy battery ?

faulty sensor ?

Battery good was thinking sensor, anyone able to shred any more light

Steering angle position sensor is a common problem with the earlier Fabias (think its called the yaw sensor). Not sure if its failure gives these symptoms though.

Any chance of getting VAGCOM hooked up for a scan?

I think you have 3 options here , Steering angle sensor , Power steering pump , or steering rack. If I was you I'd visit the nearest Church and pray its the sensor! IIRC the pump is about

Battery good was thinking sensor, anyone able to shred any more light

Power steering has its own battery - did you check that one or the main one?

the first thing i would check is if there is enough fluid in the system