Jaycar Speedo Corrector

[No1Vic]

No worries, I'll take pics and show which wire goes where when I fit it. Think I will be tapping into the speedo sensor wiring side of the plug to the instrument cluster and tuck the unit behind the headlight.... before I start anyone else know what wire does what from the sensor, looking at the wiring diagram Green is earth, then Brown/White and Black/Red unknown from the diagram but both go to the instrument cluster.

[SpudRider]

When you are under the dashboard, I suggest you unplug the speedometer from the sending unit. Then turn on the ignition key, and probe the speedometer plug with a digital multimeter to determine which of the two wires in question sends 12V DC to ground.

[No1Vic]

Had the voltmeter out and pulled the sensor plug off, black and red was at 12v while the brown and white was a lower voltage so going to assume that's the signal wire, might get some one to spin the front wheel and watch the voltage to be sure tomorrow.
Right after further testing and the speedo sensor wiring on my RX3 is
12V : Black/Red
Signal (8v that drops as the wheel is turned) : Brown/White
Ground : Green

[SpudRider]

I agree; it sounds like the black/red wire is the 12V DC wire. The wiring for this corrector couldn't be simpler. Hook up one pair of wires to 12V DC and ground. On the other side of the box, cut the brown/white wire which transmits the signal from the speedometer sending unit. Connect this wire from the sending unit into the box, and connect the wire from the Speedo Corrector to the speedometer.





I really like the quality of manufacture for this Jaycar Speedo Corrector. I think this unit represents an excellent value.

[SpudRider]

Will this unit fit under the pillion saddle? I wonder if placing this unit under the pillion saddle will make it either difficult, or impossible to install the pillion saddle?

I could make a mock up with the same dimensions, and test the fitment, but there is no mock up which will test as well as using the real item. Vic, would you mind testing the fitment of the Jaycar Speedo Corrector under the pillion saddle?

[No1Vic]

It would easily fit, here's its actual dimensions 64mm x 46mm x 25mm I have my bikes alarm siren fitted under the pillion seat which is larger than that.

[No1Vic]

Just a thought, as anyone on here had the actual speedo instrument unit apart, any jumper connections or 'secret' reset buttons on the circuit board? Can't believe Zongshen have factory set every unit for a 21" front wheel......

[SpudRider]

If you take it apart, I think you will be first.

[SpudRider]

Originally Posted by No1Vic

It would easily fit, here's its actual dimensions 64mm x 46mm x 25mm I have my bikes alarm siren fitted under the pillion seat which is larger than that.

Thanks for the verification; that is good to know.

I think I am going to mount my Jaycar Speedo Corrector under the pillion saddle. I can tap power controlled by the ignition from the flasher relay, tail light, et cetera, and I can always find a convenient earth ground. Then I only need to run a pair of wires to the dashboard; extension cord wire is fine for that purpose, and inexpensive. Placed under the saddle, the Jaycar unit will be easily accessible for calibration, whenever I choose, and it will also be located in a dry environment. In addition, space under the dashboard is crowded, and the installation will be much easier, and quicker, by placing the Jaycar unit under the saddle.

[oldqwerty]

I don't see anything trick in the Jaycar pic. Any components under the circuit board? The hardest part of reverse engineering what I see might be finding the correct triac, but I'm pretty sure I have some that will work from some homemade anemometer projects.

[SpudRider]

Originally Posted by oldqwerty

I don't see anything trick in the Jaycar pic. Any components under the circuit board? The hardest part of reverse engineering what I see might be finding the correct triac, but I'm pretty sure I have some that will work from some homemade anemometer projects.

I think they did a nice job, but I don't think there is anything 'trick' about the design. Follow the links on post #2 of this thread, and you will find a circuit design based on a $10 chip.

[SpudRider]

Okay; I finally figured out the Jaycar website.

You can have the Jaycar Speedo Corrector shipped directly to your home in the United States for a price of $29.00 for the unit, plus $7.50 shipping, for a total cost of $36.50. The estimated delivery time is 5-10 days. The potential group purchase is not significantly less expensive, or faster, than ordering the unit for yourself. Therefore, the potential group purchase is cancelled. I just placed an individual order for one of the Jaycar speedo correctors, myself.

If you wish to order one of these units, go the the Jaycar website for prices in U.S. Dollars, located at the link below.

http://www.jaycar.us/productResults....&SUBMIT=Search

So far, I have not received a reply regarding the water resistance of the unit. If I do receive a reply, I will post it on this thread. If you want to order one or more of these units, but you can't figure out the website, let me know, and I will post a tutorial thread on the topic.

[No1Vic]

Oh dear..... fitted it and nothing.... followed the instructions, test run for 5 mins so see if the LED would flash to indicate its receiving a signal it can understand but no joy :-( Swapped the jumper from 8v2 to 5v setting and tried again....no luck. Tried the other jumpers same result. Maybe I've got a duff unit or it's not compatible with our speed senders...... Looks like fitting a 21" front wheel instead.

[SpudRider]

Originally Posted by No1Vic

Oh dear..... fitted it and nothing.... followed the instructions, test run for 5 mins so see if the LED would flash to indicate its receiving a signal it can understand but no joy :-( Swapped the jumper from 8v2 to 5v setting and tried again....no luck. Tried the other jumpers same result. Maybe I've got a duff unit or it's not compatible with our speed senders...... Looks like fitting a 21" front wheel instead.

Thank you for informing us of the problem. I appreciate your willingness to test the unit, and your promptness in letting us know it isn't working.

[No1Vic]

The only thing I didn't try was reversing the sensor in/out connection, I've ordered a VDO M3 cycle computer now to provide an accurate speedometer..... ways and means to the same end I suppose.