My reverse lights don't work . . have an automatic . . when they were 'going out' used to be able to move the 'shifter' just right so that it would light the rear. . . . removed the carpet, pulled out the central heater vent, unscrewed the 'shift box' and have sprayed wd40 on the contacts . . . nothing . . .  happens . . . the bulbs in the rear are good . . . not sure what to do .  .  .