I have OEM meriva dashboard. I think, there is some problem (not mechanical) with tachometer movement - when I turn on ignition, speedo goes to max, and waits for tachometer to reach max revs. This takes about 3 sec, then tacho falls slowly, and speedometer instantly. What is more, speedometer reaches maximum just as I drive over 160km/h. Do you have any idea, what can be a problem ?