1998 Rear Diff Lock/ CD player problem
 

I just bought this 1998 Full size Montero, 138 K . Went off road last week end and now the rear differential lock does not lock. Was working before last week end. I checked all the fuses and could not find one that controls this. Also, it has a single cd player and a disc changer in the back. Neither one works. I get an error code "E 01" when I try to play a cd. Anyone have any ideas?
Thanks in advance.