For what it's woth, all my dash switch module PCB issues suspiciously coincided (precisely) with my attempts to use Morgan's fog/driving light wiring tucked away within the factory loom.
I can't categorically prove activating the factory auxiliary lihghting circuit caused my PCB issues, but the coincidence was uncanny, the circuit also never functioned reliably giving a sucession of blowing and melting fuses accompanied the myriadad PCB issues.
My advice to anyone looking to fit fogs/spots is.... don't use the factory loom, it's just not worth the risk
Before replacing my fried PCB with a later fuse protected version (yes Morgan completely failed to correctly fuse protect my original 2011/12 PCB), I installed a stand alone auxiliary lighting loom instead, this was actually the original way I'd planned to wire my fogs, but that's another story
My superior stand alone fog light wiring of course uses a relay and is also properly fuse protected as you'd expect, TBH I don't really need a relay as I'm running LED bulbs in my Marchal fogs but the job is now done right, and should I wish, I can always fit the original incandescent bulbs (highly unlikely). A decent LED bulb in the rear fog light thats switched through the PCB completes the job, my hope is I'll now enjoy reliablity from my replacement late model 2018 4/4 fused protected PCB.
If anyone is interested, Morgan used a patch cable on the 12 pin connector to add fuse protection to later PCBs, actually it looks like it was designed to be retro fitted to earlier cars as part of a recall. For anyone still running no fuse protection to their fully functioning earlier PCB, this patch cable would be a very sensible mod, indeed it would be straightforward enough to make your own.
Adding fuses to protect the delicate tracks on the PCB, fitting an LED bulb in the rear fog light to take load off that circuit, and avoiding the temptation to use the factory auxiliary lighti wiring would all be sensible precautions if my experience is anything to go by
Dave.
