Hi all, No I do not mean that type of speedos… Occasionally when I turn the ignition on, my speedometer needle goes to the max the miles start going up really fast whilst the car is stood still - with or without engine on. I did 5miles yesterday just moving the car into the garage. Speedo sensor on gearbox was disconnected on one occasion and connected on the other. I took the Speedo apart and could not see anything concerning. Has anyone got any ideas?
This has happened a few times over the years.. https://www.ferrarichat.com/forum/threads/mondial-odometer-like-a-slotmachine-crazy-problem.389586/#post-141895561 My guess is there's a fault with the small circuit board behind the odometer / clock. It supplies / receives the speedometer sensor signal, but also sends pulses of 12v to the stepper motor that drives the odometer gearing. If you're lucky it might be a cracked solder joint that is causing the intermittent problem. I had to swap mine out for a replacement unit - the PCB cannot be bought separately.
Thanks very much, I reckon you are right. I did find some surface corrosion on it, it cleaned off, but perhaps it blew something in the process. I will have to start looking for a speedo and will also try soldering some joints. In the meantime I guess it will be a gps speedo for me!
