12V Power Supply
The LS1 coil can draw up to 10A. If high rpm and high power is being used, together with conventional 30A Relays to provide power, it may be necessary to have a separate fuse and relay for every pair of coils. This is rare but it is possible.
If the wiring is also not cable of supplying the current required it can also limit the spark output.
The number of grounds (2x) on this coil often cause confusion. If in doubt, all grounds can be joined together and run the to cylinder head. This can eliminate issues if there is a poor engine ground strap that then pushes high current through the coil. It can also prevent a coil from firing if the engine grounding is not sufficient, and this happens as the ground lifts on the ECU signal preventing triggering. The fix is of course to improve the engine grounding.
Ground Pin A should go to the Cylinder Head and is the return path for the spark
Ground Pin B should go to the ECU Signal Ground and is used as a reference for the ECU Ignition Output.