Quote:

.... exactly where is this diode pack and what's it for?



The diode pack is buried in the main harness; it's function is per the wiring schematic below to interlock the starter for safety requirements, so that it is not possible for the starter to operate when the bike is in gear, without the side-stand being up and the clutch lever pulled
i.e. it is not possible for the bike to inadvertantly lurch forward by the starter action.



The Starter relay actually has a dual function - it serves as both a 'gateway' between the 'start' signal to the starter solenoid, but also cuts power to the headlights during the period the starter is being operated.

The positive (+12V) 'control' signal to energize the relay comes directly from the starter button via the White/Red wire to pin 6;
however the other terminal of the coil (via the Black/Pink on pin 4) has to be at 'ground' potential in order for the relay to turn on.
That signal comes from the 'Diode Pack' which you can consider as a Logic 'OR' gate.
The two inputs to this 'OR' gate are from the Neutral Switch to one diode, or from the combination of the Clutch Switch in series with the Side-Stand Switch on the other.
Now - an 'OR' function means that if EITHER OR BOTH inputs are at 'Ground' potential, then the output will be also.
Conversely, the only time the output will NOT be 'ground' is when BOTH inputs are NOT Ground.

So this satisfies the saftey requirement that says to operate the starter either
a) The transmission must be in Neutral
OR
b) The Side-Stand MUST be 'UP' and also the clutch lever must be pulled
OR
c) Both a) & b)

Hope that helps explain its function
3spirit has a problem where his Igniter does not appear to be providing spark and questioning the application of the Diode Pack in this regard. The Diode Pack itself bears no consequence on the Igniter (only the starter relay) - however the same input signals (Side-Stand & Neutral Switches DO go directly to the Igniter to provide similar interlocks which will inhibit its operation under similar cicumstances. This time Clutch switch not a factor, but if the side-stand is 'down' while the bike is NOT in Neutral, it will inhibit the Igniter. This is a safety feature to prevent riding off with the side-stand down.