We have no lights or anything, but we have power to the gauges and no warning lights after the initialization sequence.
The bike has wiring that goes to connectors to the things pictured below which I believe are coils and then to the spark plugs...is that what you're asking about?
You have in your hand a stick coil.... I understand how they work, more or less -- because they have to work just like a traditional coil. When you supply the coil with a source of voltage, current flows through it, in the direction of the spark plug. As it does so, EMF is generated in the from of a field that surrounds the conductor. As long as the current is flowing, the field builds to some level -- it is the flow of electricity that maintains the field.
When the flow of electricity is stopped, that field collapses in an instant. When it collapses, all of the strength of the field is converted to Voltage. It's easy for that Voltage to reach 25,000 Volts, but only for an extremely short time...... it's the exact same amount of energy, released in 1/20,000 of the time it took to store it up in the form of that field.
The Voltage is so high, the potential can arc across a gap..... the spark plug gap between the electrode and the ground. A nice big fat blue spark is a very energetic spark, compared to a weak orange one.
Old style distributor ignition systems used to use breaker point systems to allow the flow of electricity into the single coil while the points were in contact....... 'breaking' the connection on the 6 or 12 VDC feed, is what made the field collapse, and discharge into the 'high tension' circuit.... through the center electrode in the distributor cap, across the rotor, and then down to the spark plug at the end of the high tension lead.
First improvement was to get rid of the contacts because they wore away over time... that was the start of 'solid state' ignitions. Transistors replaced the breaker points, but still relied on a single coil, and the rest of the spark distribution system. Timing of the spark was still driven by the gear set run from the crankshaft of the motor.
As electronics have become less and less expensive, and smaller, many of the functions can be made smaller and more reliable....
Somewhere along the way, somebody figured out that the shorter you can make the high tension/very high voltage part of the path, the less expensive the cables up to that point became. You need very little insulation on a 12 V cable..... far less, than on one carrying 25,000 V.
With the stick coil, I think all you can do is as mentioned above...... place the electrode of the plug near the frame, and turn the motor over and see if you get a spark from the plug installed in that stick coil.
I suspect that the ECU provides that stick coil a 12V signal for a certain period of time, then shuts it off so the coils' field collapses, and discharges through the plug. Because the ECU simply needs to know where the crankshaft is, and can then do all of the math to make sure the right plug is going to discharge at the correct timing for best power (all through referencing a 'look up' table in it's Erasable Programmable, Read Only Memory (EPROM)). the 25 KV spark energy is only going through the stick coil to the spark plug itself.... well insulated with heavy plastic, and buried inside the valve cover.
Safe, and nearly fool proof.