I have a 2006 F75 four stroke that the tach is stuck on 1000 RPM. Does not move regardless of engine on or off. There is 12.7 volts to the appropriate connections on the back but I don’t know how to check the signal from the motor. I have a DVOM but it does not have a HZ reading.
I did move the calibration dial back and forth several times and returned it to the original setting (5). As I understand it, this is to remove any possible corrosion from the contacts.
All help is appreciated.