Can any one help I am now tearing my hair out, i have a fault with my omega 2.5 estate (R Reg) where, sometimes from cold and damp, my speedo will work, however after 10 miles or so, it stops working, the rev counter works fine, unlike some of the other problems I have seen my ABS and Traction control lights DO NOT lite up its just the speedo, I have taken it to a local auto tech and he chnaged the gearbox senosr at a cost of £130, but I still have the problem and to make matters worse I have now been done for speeding (my judgement of the revs was not as accurate as I thought)

As far as i recall the speed sensor is the n/s rear abs sensor.