I have a electronic tacho which I can't get to work at all. I do know a little about electrics but need more help or direction.

There are 3 wires from the tacho, LIVE, Earth, and wire that goes to the CDI (ignitor box).

Is there a way of checking the yellow & green wire from the CDI?

Is there a way of checking the tacho?

I do have a multi meter if someone can tell me what to do?

I managed to get the temprature gauge working ok. I'm having to do my own wiring as it's a race bike without many junctions conectors.

Anyones help appreciated. Rob.

 

If its in your F2, then I'd venture to say it's not stock. Can you give us the make / model?

Without specific info, here's an educated guess:

Live is your power to the tach. I'm willing to bet you should be getting a 12v reading from that line, and it probably runs to your battery, or the fuse box.

Earth is your ground. Use the continuity tester to verify continuity between this wire, and your battery's - terminal.

The CDI wire sends the information from your CDI to the tach. It probably also tells the tach when to turn on and off, so it doesn't stay on all the time and drain your battery. Can't do much with that beyond making sure both ends are connected. You could hook a volt meter to it and see what it does. It should have SOME sort of output if the bike is running, and I bet the voltage changes when you rev the engine.

If all of that is OK, then you probably have a burnt LCD.



This should at least net you some troubleshooting clues.

 

Ok here it goes.... The bike is a CBR600FM and the clocks come off of a VFR. There is definatley live power taken from the ignition switch which also runs the temp gauge. The earth is ok which is also shared with the temp gauge. Temp gauge works fine.

The doubs I have is the CDI yellow & green wire, how to check this or more to the point what does it actually do? Or is the tacho itself duff?

 

Here are the VFR clocks forget the speedo.
http://www.horrible.demon.co.uk/images/rvf_clocks.jpg

 

See above. Check your connections with the multimeter, don't just eyeball them. Pretty much all the options I provided apply to you.

 

All checked, I have 12v at the power source, I have continuity at the earth all with a multimeter.

But how do I check the CDI pulse wire on a multimeter?

 

The manual for my F3 states the Green/ yellow wire that comes from CDI should be measured with a peak voltage tester. This is an add on to your multimeter. Peak voltage should read 10.5 volts. Less than 10.5 and the CDI is the problem. Otherwise the tach is bad.
Good luck
mikey

 

Thanks for that I will give that a try. Is that 10.5 volts DC?

 

tachometer's electronic ones are pulse counters so yes square wave DC if you really want to check it use an O-scope, but doubtful that you would have one sitting around; also you would have to know the RPM-frequency that is supposed to be generated. Also the 10.5 is DC that was described. The peak function just allows you to know that the CDI is outputting a square wave signal that can be counted as a logic high and low with the Tacho- thus you get the counting and your visual/mechanical output as RPM's.

 

+1. Best you can do with the multimeter is hope the wave isn't pulsing too fast for your multimeter to pick it up. Basically it sends out 10.5v pulses in rapid succession in time with the shaft rotation.

But really, if you're getting 12v into the tach, it should at least light up and read 0. So, I think we've concluded you've got a fried tach here.