Hi everyone, been trying to hook up a tacho to my 07 Streetbob without much success. 

Yep pin 3 is where ya want t be.

I ( me that is) would cut black wire and join (green?) wire from tacho to pin end of it.

Thanks Gnoo, might try that, I wonder where that black wire goes to , no mention of it in the wiring diagrams

Black is usually ground, see if you can follow it and confirm. don't understand why tacho output would be earthed though.

Have you had bike from new, previous owner could have run a tacho and only had black wire ?

Had the bike since new, so those wires are all stock, that's what I can't understand, as you say black is usually an earth, the wiring diagram shows pin 3 on the ecu plug as 'tacho ouput' but no actual wire coming out from it for a Streetbob. It also shows pin 1 as unused but as I said all three pins (1/2/3) have black wires coming out? Here is the  link to what it should look like

Done mine (07 fxst) some years ago, pin 3 was vacant,

would have thought dyna would be the same, seems not.

Just a thought : mine is an 06 year of manufacture,

if yours is an 07 year of manufacture it may have the newer wiring on it.

Have a look inside headlight shell and see if you have a PINK wire in there.

Hey Gnoo, yes I do have a pink wire in the headlight, but I don't use it as I fitted a Fatboy headlight several years ago and didn't need it. What's the significance?

Don't know what the significance is,,, but,,,

I'd (me that is) join the tacho wire ( that's meant for pin #3) to it

and see if tacho works. I'm think'n it will.

Hi Gnoo, tried it mate but no success, I am at a loss, the wiring diagram doesn't even show a pink wire to the headlight? How did you know there might be one there? The ecm plug wires don't match anything like the wiring diagram either, makes it hard. Thanks for your help buddy.

I think 08 up you tap into the pink for tacho.( I'm still a bit confused from the 70's )

All I can suggest is go back to plan one and cut black coming from

pin3, if things go t shit, join it back up again.

Thanks Gnoo, my diagrams are the same, anyway I did what you suggested and went back to plan 1 and joined the tacho to pin 3 on the ecu plug, I just cut the black wire and connected in the tacho and shabam! it worked. F knows why they decided to wire in pin 3  when 07 Streetbobs don't have tacho's. It would have been nice to know where that black wire went too, m ight have made it easier. Anyway now to tidy everything up, for anyone out there with an 07 Streetbob or come across their ecu plug with pin 3 already taken, just wire it up with an inline splice or such. Thanks again Gnoo for taking the time to help mate.

All good mate, glad ya sorted.