Works on my 103 just fine.
All you got to do is take the ht
power lead from the stator split it into 2 leads.
Wire one lead through both of the switches then to the HT coil power input connection.
The frame is now the ht ground.
The other lead will go through the tail light and to the HT coil power input connection.
When the brake is applied the power will bypass the switches and the power will go through the brake light bulb then power the HT coil.
It's not rocket science man it's just wiring 101