Had a problem with a noise from the dashboard and a couple of times when on the motorway the noise would get suddenly much worse and high pitch - speedo needle would shoot around to 120Mph or so when the car was still only doing 50Mph!!
This would go away by slowing the car right down and things would return to normal.. At present this has only occured when the car is cold in the first few miles of a journey.
To me the initial noise sounded like the speedo cable whirling around then when the Speedo needle went funny it was as though the cable was getting into some sort of high pitched mad resonance..
Now I've changed the speedo cable and first impressions are I still have the problem. I'm now thinking its a problem with the Speedometer itself or with some head unit at the back that the speedo cable clips into??
Has anyone any experience or thoughts please? I'm thinking there may be an transducer at the back of the speedo that converts the mechanical movement of the cable to an electrical signal that operates the speedo needle.. And I may be able to replace this part?
Jeff
