Hi, after much thought, I decide to change the cog myself on my 1986 911 odometer, as it had deterioated and didn’t record mileage. I labelled all the wires when I took the speedo out, and then plugged them in again after the cog change. The issue I have now, is that as soon as I turn the ignition on, the speedo shoots all the way around past the top speed and hits the odometer reset switch. If I turn the ignition off, then the Speedo arm returns to the 0 mark. I have no idea what I have done to upset my speedo, but it’s not happy with me. Any help/suggestions would be very much appreciated. I thought I was saving money by doing the odometer cog myself, after watching numerous YouTube clips… and now it looks like I may have to end up spending money to rectify the new problem.
