speedo and rev counter eratic

[johnrolfe]

hi all i have a 1.8 sri vectra c 2002
ive just had a load of unusual faults just lately such as
speedo and rev counter moving up and down on their own with car ticking over also radio cuts out interior light switches on and off petrol gauge moves up and down warning alarm goes off and the engine warning light has now come on.anyone got any ideas???

[Ste]

SOunds a bit like voltage regulator going faulty to me. Can you measure the voltage when the car is idling?