I recently acquired a 2000 500 Sportsman 4x4 that I've been working on. The bike was in pretty good condition for it's age, it mostly needed a lot of maintenance that was let go, and had been sitting up for a long time. I've got the bike all fixed up and working well now.

However, the speedometer is not measuring speed. I've read about the speedo dying and causing other issues, but I din't think that's the case with this one. the 4x4 is still wired through the speedo and works perfectly. Reverese override button is still connected and works, the speedo lights up at night, counts hours, etc. The speedo needle just doesn't move, and it doesn't count miles on the odometer or trip meter.

On the parts fiche for this year, they give two part numbers for the hall effect sensor in the front right wheel, one if built before August, one if built after. Mine was built in December according to the sticker on the front. So mine SHOULD have the metal cap over the sensor, but it doesn't. The cap is missing. Would this cause the sensor not to work? Is the cap just protective, or is it necessary for the sensor to read and send pulses to the speedo?

I remember reading somewhere that you can built a simple "test light" with a 9V battery, LED, and resistor of a certain value, but I can't find it again. I would like to try something like that before buying a new sensor.

I would also hate to buy a new sensor if all I need is the metal cap... lol

If it turns out I need a whole speedo, then I'll probably just live with it the way it is. They are a little bit above my remaining budget for this project... lol

Thanks in advance!
-Keith

 

Hall effect sensors bit the dust regardless of whether they had the metal cap or on early models that didn't. Cap is just protective,but not absolutely sure the older model sensor will fit into the cap,but "fairly" sure it will.It's about 10 bucks over the price of the sensor. Since the rest of the speedo works,pretty sure the hall effect sensor is shorted out.

 

Thanks for the quick reply! I'm pretty sure it's the sensor too, I assume it is since the rest of the speedometer functions, as you said.

My biggest concern was the missing "cap" on the sensor. I wasn't sure it it is just protective, or effects how the sensor works or not. I know they work with a magnet and sensing the metal in the brake disk as the holes/slots pass by the sensor. I wasn't sure if that metal cap has any part in how well this all works... lol If the sensor should still function even with the missing cap, I'll just go ahead and pick up both a new sensor and the cap to go with it.

I guess I could try ordering just the cap first and maybe my old sensor would work with it, but I'd hate to waste time and extra shipping money placing two orders just to try and see.

I will update once I've had a change to get the parts and figure it out.

Thanks again!
-Keith

 

Just a quick update. I checked the pins in the back of the speedometer for the speed sensor. The ground pin is grounded, and the pin that supplies power to the sensor has about 7.5V on it. Testing the sensor shows infinite resistance across all wires. Powering the sensor with the speedometer and testing the signal wire only gives 4.5V that never changes as the wheel is rotated. I'm pretty confident now that the sensor is the issue and have ordered it along with the missing metal cap. I will update again once the parts arrive and I've had a chance to git it fixed up. I hope it works!

 

That does sound like the sensor has faulted. The test kit we used looked for the same thing on voltage change.

 

Just a quick update to end the thread.

I got the "new" sensor and cap today, actually used parts from eBay. A seller took my best offer of $15, better than paying for a new one! I swapped it out and everything works as expected, the speedometer and odometer works, trip meter too.

Thanks for the help!

 

That's way better than what a new one costs.