No Inrush issues.
I also note the above paper seems to be referring to a 240/110v AC mains wiring system in a house, so I'm not sure how relevant it is in an automotive 12v DC situation? I certainly ran LED H4s in my TVR for years and never suffered any such inrush issues.
One thing I can confirm is the Marchal LEDs have massively lowered the load on Morgan's embedded aux lighting circuit that’s protected by fuse 12, to be sure on this I have multiplied the total bulb Wattage on the circuit and carefully logged my battery voltages too using my EMU Black ECU software that confirms the alternator regulates perfectly between 13.4v - 13.7v.
Based on my calculations, and now supported by real world testing the 5a fuse 12 I'm running has proved itself to be perfectly sized. However, given that the dip & spike on starting is where I'm most likely to experience an issue I repeated a number of consecutive cranking tests with the Marchals left on, and I'm pleased to confirm all was fine thumbs
A little confused by your logic in reducing fuse 12 rating to only 5 amps now Dave. As you are aware this fuse covers the offside side lights and dash illumination and it's rating of 7.5 amps was chosen by the factory, with same rating fuse 11 for the independent nearside sidelight circuit, to cover the loads from OE filament bulbs. The previously redundant dedicated wiring in the loom you have employed for your fog lights takes its power from the same o/s circuit/fuse, so you have therefore
added to the ex factory load albeit by only a small amount now by using LED bulbs. It seems odd to me therefore you now choose a
smaller rating fuse unless it course you have changed all sidelight bulbs to LED as well
Not sure what your voltage measurements prove other than showing they are as expected. With regard to the fragile PCB board, as explained already the front fog light wiring you have employed is independent of this PCB. There is a sidelight power feed to this PCB but only to provide a conditional trigger for rear fog light when selected.
