XM control box

[xmds]

The zapper on my 2.5 td exclusive xm has finally given up the ghost. It aint the batteries; I think it is the control unit. But any other thoughts and ideas on fixing? Initially, the indicators would rapidly flash. But then one stayed on. A fuse was bridged and the when replaced by normal fuses the rapid flashing would stop but the interior light would come on when the left indicator was put on! Nightmare!