hi all

i have a 2002 vectra and quite often now my abs light comes on and all my dials stop working (spedo.rev counter,temp dial and fuel gauge) at the same time my milage stops going up. some days i could drive 10 miles befor this happens other days it happens as soon as i drive the car. i know this has been discussed befor however no one come back to say how or if they got it fixed. would like 2 know before i start changing things that might not need changed as 2 mechanics have both said it could be numerus things from altanator, sensors, abs cpu, wiring looms and dirty connections

any help would be appreciated thanks