Many times on switch leads, the proper curcuit colours are not maintained. Go to the connector at the chassis harness, and note the colours, there. The connector only plugs in one way. The 12 volt switched source for the back-up lights should be white with pink, and the switch out wire to the lamps should be black with pink.
For the start circuit, circuit 32, the wire colour should be red with light blue. 12 volts comes from the ignition switch only in the start position, and goes to the "S" terminal of the solenoid on the fender apron.