Im Having A Tacho Nightmare

I'm no expert but I would think just adding it to a bracket won't make it work maybe a wire or two connected to the appropriate parts may help. (I thank you)

 

Keeping it dead simple.......

If you actually have a T100 it would already have a tachometer . Assuming therefore you have a regular Bonneville you need (in addition to the bracket) a piggy back live feed and neutral return to the adjacent speedo to illuminate the instrument. A tachometer essentially counts sparks. The tacho -ve goes to earth. The +ve should be fed by a red cable from the ECU but a simpler method is a direct feed from the ignition coil +ve 12v terminal. Use black wire and tape it to the main harness to the headlamp shell for a near invisible result.

 

The only potential issue is how the Scrambler tacho takes its signal. You are fitting a twin coil bike instrument on a single coil machine. I don’t have a wiring diagram to tell me if the tacho is fed by one or two coils. Check part no between 270 and 360 equipped bikes.
It will work but it might show only 50% if it needs two signals - albeit the crank is turning at the ‘right’ speed.