a "jumper" is interconnecting wire, as in "jumping the battery" - a sketch:
front
|
w
|
i
|
r
|
e
|
driver light ----j-u-m-p-e-r---- > pass light
do you have single bulb/dual filament lights?
if so, one filament [brighter] is the brake light, which also serves as the turn light, one wire for each side from the signal unit [fed by the brake light switch] - the dimmer filament is the tail, one wire from the light switch, first to the driver side, also "spliced in" there will be a wire to the pass side, so 3 wires from the front .... if you have added on turn lights, there will be a different setup
Bill