reverse lights not working

have a 72 dart swinger, and i cant figure out the reverse lights.. they worked last season and now this summer, there just dead... any ideas on where to trouble to shoot, looked at shifter, there was one wire that was unhooked rehooked it, but all those wires are dead, not sure if they will have juice to them or not.. on the transmission.. (sorry for my slander of mechanical stuff), but the wire that hooks onto that, there are three choices to plug into.. is there a certain one the wire needs to be hooked to? its connected to the middle one right now, i have no idea what that is for, im assuming that is for the reverse?....
looking for some trouble shooting ideas..
thanks
swingerwoman...
Author: admin