I asked this question in the Softail forum but didn't get an answer, I decided to post it here since there is a lot more traffic and it would still apply to a touring bike.

I have a Dakota Digital gauge on my FatBoy which has all the sensors plugged into. At low speed, the speed reading is right, as soon as I get into higher speeds, the reading is all wrong. The RPM and signal lights/hi-lo beam displays seem to work OK.
Is it possible that a bad speedometer sensor (the one on the transmission) could give a good reading at lower speed and a bad one at higher speed? I was thinking it may be the connection to the gauge itself but then I would assume the RPM would be all wrong as well. The sensor is a hall effect sensor like the crank position sensor. I've actually had one go bad in my Audi and the thing kept stalling at any time.

Thanks for any help.

 

Get in contact with Dakota Digital I am thinking that you might have to calibrate these gauges.

 

Thanks for the reply. I sent an email to Dakota. I will try re-calibrating it again and see if it works.

 

ugh...........

read your question wrong, I got nuthin

 

Electronic speedos are pulse counters (tachometers made to read in MPH) and a loose connection could generate extra pulses which would induce errors with the indication. Lower rpm might not generate the right vibration to cause the errors while higher frequency could buzz the connector. Much the same thing could happen internally in the speedo also and not cause a problem with the other functions. Start with the easy access connectors involved, take them apart and re-seat them, then move to the not so easy ones if necessary. Pulling the speed sensor and checking for "fuzz" deposits is also a free check.

 

That is great advice. I already re-seated the connections to the speedometer itself and that didn't work. Next I'll try a recalibration and work systematically from there. Like you mentioned, taking the hall effect sensor off and cleaning it is just a matter of minutes.

 

A speeding ticket would be a good indication.