1200gs electrical problem, need help

I have a 2005 R1200gs with 40,000 miles on it. About a month ago I noticed the following while riding:
Brake Failure light flashing
Turn signals not working
Emergency Flashers not working
Horn not working
Trip meter not working
Heated grips not working
Brake light on tail light not working when brakes applied
Brake servos are not working but occasionally and unexpectly work while stopping

Pretty much all electrical controls on the handle bars do not work.

HISTORY: Prior to the problems occuring I had removed the bar end and throttlemeister to see how they were attached and then put them right back on. I am pretty sure that I rode the bike one time after reattaching the bar end and throttlemeister and everything worked fine. That is the only work I had done on the bike prior to the problems showing up.

I talked to Max BMW and they suggested it might be the battery so I installed a new and fully charged odyessy battery but am still having all of the same problems.

Any suggestions how to fix? Thanks for you help

Most of the items you mention are connected to the ZFE Control Module or could be triggered by a failure of the ZFE to pass the correct information to some other control module. I'd hook up a GS-911 or the dealers diagnostic computer to read any fault codes and go from there. A shot in the dark (and likely a waste of time) would be to remove the fuel tank and re-seat the connector to the ZFE.

Thanks for the suggestion.

Thanks, I will try the code reader and see what it says.