The inside voltage guage was showing 13-16 volts (fluctuating real fast) while the hand held unit connected at the battery was showing 15.10 to 15.22 fairly slowly within that range.
Should I try the new voltage regulator?

I don't understand why one voltage gauge shows the 13-16 while the direct battery shows constant 15.1-15.2 at the same time unless the inside voltage gauge is going bad.

Robert,
My backup ECU is at FBO being rebuilt. I sure hope that the MSD is not causing this.

I could remove the fuse but both studs showed the same 15.1-15.2 which was the same as the battery voltage.

Thanks for the replies.