Tacho on Touring

Hope there's someone to tel me how to install an Original tacho on my custom build Rocket touring which is almost totally stripped en rebuild. I am using the Original clock in a self made dash-board en want to add a tacho. I'm nog sure however about the wiring. Diagrams i own are confusing me....it's my weak spot. I figured out some of the colours but i only succeeded in getting the display lightened. I hope somebody can explain the colours that make te tacho work.

13 wires with several colours.....please explain their purposes.

2x black
black/white
black/green
purple
red
brown (= display+)
green/red (blinker L)
green/white (blinker R)
blue/white (high beam)
grey
yellow
orange (0 gear?)

You are further along than I would make it, Sorry I can't help but maybe check with @DEcosse as he is the electrical guru on our machines. Good luck

Here you go - thought it better to just create a labeled diagram





Note that in English it would normally be called Instruments or more generally speedo (tacho would be reserved for specifically a tachometer measuring engine rpm that the touring does not have)

If you are adding a non-OEM tacho, then there is no discrete signal available for that function which you can extract from the CANBUS system.
The CANBUS lines carry the signals digitally for the Speed, Fuel, Engine Temp, Engine Warning Light etc)

To add a tachometer you must take the signal directly from one of the Ignition coils - you should follow the manufacturer's instructions for the specific tachometer you have purchased.

@DEcosse help me out here. There MUST be an RPM input. How else can there be a map that adjusts fuel mixture by RPM ?

Why is that not available for tapping (if one had enough money and time) ?

Does the Roadster have a different ECU that offers out the tach signal ?

The CPS (Crank Position Sensor) provides the timing and rpm for the ECU
That is a low level signal, insufficient to drive a tach - plus there are many more pulses in that signal per engine revolution that would equate to engine rpm directly
So the only way to drive a tach is by using the coil signal which will directly give you a correlation used by most tachs and at the correct voltage

On a Roadster the Tach Signal is also encoded in the CANBUS data stream along with those other functions mentioned above (speed, fuel etc)

I should add some notes about some of those signals:

The Black/Yellow is a switched OUTPUT 12V supply for the speed sensor - some could be confused and since is connected to the sensor may think this is the actual speed signal, but it is 12V OUT, not input.
The speed signal itself from the sender goes to the ECU where it is processed into the Digitally encoded signal onto the CANBUS to the actual speedometer.

The turn signal wires:

The Light-Green/Black is the 'enable' to run the actual flash generator which is contained within the cluster electronics; this is a 'low' (ground) signal and comes from the turn signal switch (whether switch is moved to left OR right);
the turn signal switch is actually a dual pole switch - one pole sends that ground to make the flasher run;
the other pole then directs the flashing signal to either the left or right sides.
The Light-Green/Brown is the pulsing output from the flash generator which goes to that pole on the turn-switch to be directed to left or right.
The Green/White and Green/Red are then INPUTS to the speedo, simply to mimic the bike's turn signals, displayed on the panel.

DEcosse

Thx for te big effort to inform en instruct me. I think i have to find a way to "pass-by" the Original wiring. I bought an origninal Rocket classic tacho and want to install it on a Touring. I guess i have to deal in the way you explained in the text below.

"To add a tachometer you must take the signal directly from one of the Ignition coils - you should follow the manufacturer's instructions for the specific tachometer you have purchased."

I made a list of the wiring of the tacho and i hope , maybe you have knowledge what colorcombination can be tried in an experiment on one (two or tree?) ignition Coils. probably even in combination with something like a condensator?? I'm a dumn ass with electronics but i guess its no "rocket-science" to make it work. (what a nice choice of words!)

A condensator???
Didn't they have one of those on the Back to the Future DeLorean?

You only need signal from one coil and it does not matter which one
I'm not sure whether the OEM classic tach is 5V or 12V - I suspect 5V however - I would certainly start with assuming its 5V and use a 'conditioning' circuit t achieve that ....

You need two very simple components -

Thx again...but...i'm quiet sure about several colours on the tacho i mentioned but still i'm confused which colour has to make the tacho work.
Most likely purple, grey, Yellow, orange or red? do i also have to connect one of te blacks for ground?

I presume you have the OEM wire sub-harness for the speedo/tach from the early generation bike?

You need the following connections

Function - Old Harness* - Touring Harness

Tach Signal - Red - Connect to Coil 1 negative (Green/Pink) using components in post above

Illumination - Red/Blue - Green

Switched Power - Green/Red pin 2 (NOT pin 7!!) - Green

Constant Power - Purple - Purple

Ground - Black pin 10 or 12 (NOT 11 or 12) - Black pin 4 (NOT 5 or 6!!!)

* These pin numbers correspond to the 16-way connector common to both speedo and tach that plugs into the OEM main harness.