Wilson, the last regulator that should be fitted is the standard, original fitment one from Morgan. It appears to be vulnerable to internal failure due to heat and/or vibration plus the quality of the external wiring is poor leading to breakage of the copper cores and cracking of the insulation which leads to short circuits and early failure.
I have no idea why MMC persist with the original regulator, it just seems to be such a poor bit of kit. On the other hand the cheap, "for Harley" regulators direct from China via eBay just work.
