yeah they can plug in a few ways
best way is stick it in reverse with the ignition on and the plug on the car side that has a red and yellow pair of wires, plug em into the switches in the box and when the reverse lights come on, leave it in that plug and take it out of reverse, if they go out, thats the right one, if they dony, try another one
there are switches for reverse, 5th and 4th on some boxes for the pollution garbage