:Back-up lights

I can tell you that the hot feed for the backup lights comes from the wiper switch. The wires for the backup switch are white and purple with white being the hot feed and the purple being switched. Since you have a 4 speed, the wires will run through the firewall to the tranny. You may wish to check you firewall connector for any signs of melted or shorted wires first. If your wipers are only working with the key on, that is not the source of the always on hot feed to the backup switch. Something else must be shorted down the line to an always on hot feed. Wiring is not real fun to trace down but at least you now know what color of wires to look for and where the hot feed should start to that circuit. Check the wiring at your wiper switch for possible shorts as well.