Ok, found it. And it might be a problem on other X5's.

The cable to driver side, post catalytic converter O2 sensor was rubbing on the transmission output yoke. It shorted against the driveshaft. Big surprise that a section of cable was loose and could touch the driveshaft since all the other O2 sensor cables are routed and clipped against the transmission. This one spot would be logical to tie down better to avoid the driveshaft, but it was looped and touched over time wearing through. I fixed it, replace the fuse and everything is fine.

I will include a photo of my fix when I have a chance since i added a small plastic loop held by a self tapping screw in a place on the rear of the transmission that looks like it was meant for this, to keep the cable away from the driveshaft so this doesnt happen again.

Problem solved. I would check other 2003 X5's to see that the cable clears the driveshaft. A pain to find but glad I found it and could fix it.