thecarfixer said:That voltage reg is toast. Possibly diode(s) too as there's loads of fluctuation so you're probably hitting everything with AC.
I wouldn't run that until fixed!
Yes, looking at the video it does look like the rectifier is possibly fubared too, you need to test what AC ripple is coming out of the alternator, should be below 100mv AC. It might just be the voltage regulator though and the control units are protesting on overvoltage.
Multimeter on AC setting, black lead to chassis, red lead on B+ alternator post is best, but battery + Post will show most of the ripple, but dampened by the battery, less than 100mv but 50mv is normal.
I`m thinking more and more that this is your rough running issue Chris :thumb: