Speedometer / tachometer issue

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tunderwood01

New Member
Well here goes my first of many questions.
When I turn the key on the Speedo jumps up half way then drops to normal. I think from what I’ve read that is normal but upon driving the Speedo doesn’t register at all, distance or speed.

Now the tach issue:
When I turn on the ignition and start the bike all of the led’s come on which I read could be the signal wire.
Is there any common item that could be the cause of both issues? Or are they separate independent issues?
 
T

tunderwood01

New Member
Quick update.
speedometer:
So I have continuity in green signal wire from the speed sensor to the back of the board on the speedometer. I also have the correct pulse count. I did notice that the black plastic housing was cracked where it seems it was over tightened to the bracket. Not sure if this could be the problem or if it’s the speed sensor but it doesn’t seem to be the wiring. I thought I saw somewhere how to test the speed sensor by spinning the wheel but I couldn’t find that procedure to save my life.

Tach:
I have continuity from the ignition module all the way to the led ring of the tach. One thing to note is that when you turn on the high beams the blue indicator does not light up on the ring but the turn, neutral and oil lights do.
 
Mickmorris

Mickmorris

Well Known Member
Supporting Member
tunderwood01 said:
Quick update.
speedometer:
So I have continuity in green signal wire from the speed sensor to the back of the board on the speedometer. I also have the correct pulse count. I did notice that the black plastic housing was cracked where it seems it was over tightened to the bracket. Not sure if this could be the problem or if it’s the speed sensor but it doesn’t seem to be the wiring. I thought I saw somewhere how to test the speed sensor by spinning the wheel but I couldn’t find that procedure to save my life.

Tach:
I have continuity from the ignition module all the way to the led ring of the tach. One thing to note is that when you turn on the high beams the blue indicator does not light up on the ring but the turn, neutral and oil lights do.
Click to expand...
Have you removed the speed sensor and cleaned it?
 
Jersey Big Mike

Jersey Big Mike

100K mile club
tunderwood01 said:
Well I got the speed sensor out (without dropping the o ring thanks for the heads up) and cleaned it. I reinstalled it and still no speedometer. Is there a way to test the speed sensor. Before I replace it?
Click to expand...
Yes. Take a volt meter and attach to I believe the green wire
One wire is 12v, one is ground, the other is signal

Ground your voltmeter
Rotate the tire slowly and you should see it flucuate the voltage. It is imperitive that it goes to 0VIf the sensor is still out you can hook it up and use a block of STEEL and move it to the sensor to get the same results.
Odds are its a bed sensor -- SKogdog just went thru this.
 
SKOGDOG

SKOGDOG

One of the old ones.
Jersey Big Mike said:
Yes. Take a volt meter and attach to I believe the green wire
One wire is 12v, one is ground, the other is signal

Ground your voltmeter
Rotate the tire slowly and you should see it flucuate the voltage. It is imperitive that it goes to 0VIf the sensor is still out you can hook it up and use a block of STEEL and move it to the sensor to get the same results.
Odds are its a bed sensor -- SKogdog just went thru this.
Click to expand...
Yes—- Jersey Big Mike is correct—the readout will appear random, but he critical part is that it read “0” between each data point.
 
T

tunderwood01

New Member
What type of voltage should I be seeing? The most I’m seeing is 7 millivolts with the key off. With the key on it reads about 1.3volts but doesn’t ever go to zero. Not sure if it matters or what this means but there’s about 5k ohms of resistance between the signal and ground. But I’m pretty sure the switch has bit the preverbal dust.
 
SKOGDOG

SKOGDOG

One of the old ones.
I initially read the random numbers generated by the speed sensor and assumed that the since it was sending, it must be OK. So I called Dakota Digital. The tech there was very helpful and walked me thru what Mike describes above. The tech said that if, while turning the wheel slowly, the voltmeter does not read zero between each data point, the speed sensor is bad, not the speedo. He also said the specific readout numbers don’t matter—data and zeros do. Mine registered data output, but no zeros. There was a spare transmission handy, so we pulled that sensor. Installed it—voila!! Speedo works perfectly ever since. I gave the old sensor to New Jersey Big Mike at Mastiff Dave’s Farm pastry because he’s an elecrtonics whiz and wanted to do an autopsy on it…..no report on cause of death yet.
 
Jersey Big Mike

Jersey Big Mike

100K mile club
SKOGDOG said:
I initially read the random numbers generated by the speed sensor and assumed that the since it was sending, it must be OK. So I called Dakota Digital. The tech there was very helpful and walked me thru what Mike describes above. The tech said that if, while turning the wheel slowly, the voltmeter does not read zero between each data point, the speed sensor is bad, not the speedo. He also said the specific readout numbers don’t matter—data and zeros do. Mine registered data output, but no zeros. There was a spare transmission handy, so we pulled that sensor. Installed it—voila!! Speedo works perfectly ever since. I gave the old sensor to New Jersey Big Mike at Mastiff Dave’s Farm pastry because he’s an elecrtonics whiz and wanted to do an autopsy on it…..no report on cause of death yet.
Click to expand...
Damn, I missed the Pastry at Dave's -- got the brisket (hman, wonderful job) snickerdoodles (Rosalie as usual) but never saw the pastry. :oldhardlaugh: :oldhardlaugh: :oldhardlaugh: :oldhardlaugh:
Sorry Rick -- too many years working for a publisher!
 
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