Whilst I've got absolutely nowhere so far with the tacho, I have on my travels so far managed to fix the oil pressure light which also wasn't working. There is a 6 wire connector behind the headlight that feeds the tacho and oil pressure guage. The pin for connecting the yellow wire had been pushed in and was no longer making contact. Id deffo check the pins on that connector.
Evening all A bit ahead of schedule. The Scope turned up early and I had a spare hour so i went to have a play. The Outcomes are as follows: - Oscilloscope connected to Grey/Green wire at the 3 pin tacho connector, and earth to battery - Square Wave form detected (this is what it should be), with an amplitude of 1.2v. At idle the signal was running at 36Hz (which from what ive read this is correct) - Oscilloscope connected to Pin 24 at ECU and earth to battery - Identical. Square wave form with an amplitude of 1.2v at 36Hz All measurements taken with the bike at Idle. Ive taken a pic of the Scope screen incase anyone with more knowledge see's that ive made an error somewhere. Given the read outs are identical at both the tacho connector and ECU, i'm now confident that the issue isn't with the grey/green wire that runs front to back on the bike - otherwise my read outs would be different. It would however appear that the tacho signal being given out by the ECU is correct but 'weak' - I believe (and please if you know better let me know) that the signal that runs down the grey/green wire should be 5 Volts, not 1.2 Volts. I need to find this out for sure as at the minute i'm comparing my figures to rough guesswork based on various forum posts. My new oscilloscope also has an inbuilt signal generator, however it only has the ability to push 3v. I tried to test the tacho(s) with the signal generator, and whilst neither of them worked fully, both were twitching which makes me think that with the correct signal, they will work. I am going to look into bench testing them using a more powerful signal generator This leaves me with - why would the ECU being giving out a weak signal, and what can i do about it? The bike runs an absolute dream so i can't see it being a terminal fault anywhere. Any thoughts or is it time to start looking for an ECU? As always, many thanks for all your input to date. I really do hope that this can help someone somewhere along the line.
Thanks That adds some more info into the mix. My reading of that is: - 1.2v at Idle may actually be normal (or could even be an over voltage) - I should see a 10-12v square pattern at high RPM - I need to check the ECU earth on Pins 18 and 19 Anything im missing?
