Electrical problems can be frustrating Paul. Just to be sure ... You have measured 78 VAC from each of the yellow stator wires to ground at 4500 rpm. right?
If that is true, then at least the stator seems to be in good working order.
On your next try, pull the two 10A fuses on the JB (headlight and taillight). Then, check for DC voltage at the R/R. Specifically, shove the probe in the top of the pin that is just at the locking tab of the R/R connector. It will be in the middle, and not yellow. This pin is designated as "M" in the schematics. I think the wire color will be brown. Document this voltage, and then do the same for the pin with the white wire. Check them at 2500rpm, and don't run the engine long. Let us know what you find after testing the R/R pins. Good hunting ...
'91 VN750 - Cosmic Splendor/Candy Wine
Done: Coastered, .020 ign., Iridiums, VM
Plexistar II, MCCT's, Relocated MOSFET
Will Do: Horns, Shave(maybe)
Last edited by ZCraggRatt; 02-15-2011 at 03:15 PM.