I got my V35 back in November 2020, I am the 3rd Australian owner to my knowledge. I have spent the past year and a bit trying to fix all the things the previous owners have broken, much to no avail. It had 1 little gremlin I could never fix, The speedometer would occasionally default to 35 km/h and then go to 55 km/h when I started moving. It would normally only do it for 22 to 40 ish minutes, Its been doing it for now 5 straight days. Does anyone know what could possibly be the reason, I've tried taking the dash out, re-soldering the terminals, doing an ECU reset, everything but it still keeps happening. Its a 2003 5AT V35 coupe 350GT. (Note the trip meter is still getting correct knowledge of distance, it only goes up when moving and the slip light is not on) I currently have the dash out and trying everything I can, I know the most logical answer is buying a new dash but I would rather not have to.
I used a multimetre to do some poking around in there and there is a stray 0.6 volts when the key is turned to the 'On' position and increases to 0.8 volts before dropping volts back to 0.4 volts. Thank you for your time