Tachometer not working

[oz1961]

Hi everyone I hope you are all safe and well. Now this problem I am presuming is entirely my fault but I am struggling to find the solution.

I had removed my ICU box etc to change my front spark plug leads

since refitting the unit I have no tachometer working anymore

is there a plug from the ICU that sends the signal to the tachometer that I am missing?

I look forward to your help and suggestions

 

[MaxMidnight]

No, it is included in one of the multiblocks and will, depending on the year of bike be either grey up to '89 or yellow '90 onwards.
Suggest you get a wiring diagram.