I just bought this legend conversion van. It has a button on electric panel that says convenience and it doesn’t seem to do anything. Does anybody know what this is supposed to operate?? Also this van has additional fuse block in the back it has a relay and a fuse for spare battery I can’t find a spare battery the only one I see is the engine start battery does anybody have a clue where a spare battery would be hiding. Thank you for all your help

 

check the frame rails