Thanks, yes, there are six, three negative and three positive ground, so you have to be careful if you change these yourself. Needless to say, replace them all, no sense replacing just the bad one knowing all will break down eventually, so in my case, one had a corroded connector leg at base of diode, and if you pressed your lead down on bridge, it would read OK, so you really have to look closely and not go by meter reading alone. You also have to unscrew ground screws which hold rectifier to alternator base. Pretty straight forward way to repair rather than replace whole alternator, or even just the regulator, replace all diodes, regulator and check bearings for noise. Mine was quiet as a mouse, so didn't bother replacing bearings at this time. If you hear even the slightest noise, replace them. Also, the plastic bearing spacer will almost always be cracked and in pieces when you pull core, so always replace this shim.

So putting it back together and will let readers know how it all works out. I have 176K on my X5 for reference point. So I am not complaining to see a couple diodes go bad along with regulator, now I wonder if broken lead on diode killed the regulator? Again, I am old school, believe in fixing rather than replacing like dealers and mechanics all do these days. As a kid I use to rebuild generators and starters, no electronics like today, but similar in diagnosis. Hope this helps others save money over getting ripped at dealer for over a grand.