Definitely in the right direction. Read through a few different posts regarding the LCM on this and other forums on the e53 and e39 and it sounds exactly like it!
This weekend i'll pull it and see if In fact theres some moisture down there. The car did sit outside and has barely been moved for a year or more.

I'm reading that a replacement LCM has to be programmed to the VIN. can this be done on the bench or does it have to be installed first?

Thanks guys, I knew someone would point me in the right direction