If you look at the wiring diagram, the pink wire is the hot feed to the wiper switch and marked with a "B" on the switch terminal. The backup switch terminal also has a "B" terminal marking. This hot feed comes from the ignition switch black wire on the ACC terminal and is hot in both run and acc position. The ACC feed runs to the flasher unit, the wiper switch, and back to the fusebox to feed the radio, rear defroster, heater blower motor, and brake warning light on their respective fuses. So in theory, the backup lights should be off when the key is off as the hot feed has been turned off at the switch. Not to say you are wrong in your wiring being right but I would be curious to see where the hot feed is coming from with the key off. Assuming your wiring matches the diagram as shown, the radio and wipers should work with the key off as well. Now we have a mystery on our hands.