03 Road King Speedometer Reading Half

[RibEye]

The other day, my speedometer began to read around 1/2 of what it should. It had just been fine on a 6 mile ride. A few minutes later I fired it up and took off and noticed after some distance that it was reading incorrectly. After about 6 miles, I shut her down, and went in for dinner at a restaurant. After dinner, I fired her back up, and she was reading correct again.

I'm an electronic/software engineer, and the speedo is an electronic one. 1/2 is a miss of 1 bit. Can it be that the speedo just needed a power on reset (simple glitch), or is there something else I should look for?

Thanks,
Rich P

 

[softailhog]

I believe your speed sensor is going bad, it sounds like the common symptom. There are a couple of tips on the forum for testing the VSS (vehicle speed sensor) that should help you.

 

[Bodeen]

Just a thought, When you jump on to start it and you turn on the switch. Do you wait until the lights go out on the speedo? I have found if I get in to big of a hurry and dont wait, my speedo will not be accurate at all. After having said that, my speedo always seemingly read twice as fast. Hope it helps.

Bodeen

 

[Hoople]

Richard,
I don't know when the 6-speed gearbox was introduced but do you have one.
Also buy chance, do you have an instrument light that tells you when you are in your final gear ratio?
(On my 6-speed Dyna I have a light that tells me when I am in 6th gear).

 

[RibEye]

Richard,
I don't know when the 6-speed gearbox was introduced but do you have one.
Also buy chance, do you have an instrument light that tells you when you are in your final gear ratio?
(On my 6-speed Dyna I have a light that tells me when I am in 6th gear).

6-speed came in around 06 or 07. I have not gear indicator lights.

I am in the middle of installing a Scorpio SR-i900 alarm system. When done, I will remove the VSS and clean off whatever metalic fur I find. I will also immediately order a new VSS, for when this one fails...

Enjoy,
Rich P

 

[RibEye]

Just a thought, When you jump on to start it and you turn on the switch. Do you wait until the lights go out on the speedo? I have found if I get in to big of a hurry and dont wait, my speedo will not be accurate at all. After having said that, my speedo always seemingly read twice as fast. Hope it helps.

Bodeen

I always wait until the ECM indicates readiness to run (engine lamp goes out) before I start up.

Enjoy,
Rich P